Nasdaq SFNC .2 rd 3 Quarter 2025 Earnings Presentation October 16, 2025

Company Overview Simmons First National Corporation A Mid-South based financial holding company serving our $24.2 $19.8 customers and the communities where we work and live since 1903 BILLION BILLION TOTAL ASSETS TOTAL DEPOSITS $9.3 $17.2 CONSECUTIVE YEARS 3 116 PAYING DIVIDENDS BILLION BILLION ASSETS UNDER TOTAL LOANS MANAGEMENT/ ADMINISTRATION YEARS OF SERVICE 122 15.07% 8.53% 1 TOTAL RBC RATIO TCE RATIO FINANCIAL CENTERS 223 ACROSS SIX STATES 4.6% 87% 2 DIVIDEND YIELD LOAN TO DEPOSIT RATIO 1.50% 168% ACL TO TOTAL NPL COVERAGE LOANS RATIO Figures presented on this slide are as of September 30, 2025, unless otherwise noted 2 1 Non-GAAP measures that management believes aid in the discussion of results. See appendix for Non-GAAP reconciliations 2 Based on October 9, 2025, closing stock price of $19.06 and annualized dividend rate of $0.85 per share 3 The future payment of dividends is not guaranteed and is subject to various factors, including approval by the Company’s board of directors

3Q25 Financial Highlights 3

3Q25 Highlights 1 Reported Adjusted LQ Change 1 Net income $(562.8)M $64.9M 16% ❑ Completed Balance Sheet Repositioning ─ Net proceeds from common equity offering of ~$327M 1 EPS (diluted) $(4.00) $0.46 5% ─ Sold securities with a fair market value of ~$2.4B; after-tax loss of ~$626M ─ Proceeds from securities sale primarily used to deleverage the balance sheet by paying down higher cost deposits and wholesale borrowings 1 ROAA (8.96)% 1.03% 19 bps ❑ Strong-top-line growth 1 1 1 ─ Adjusted total revenue up 9% and adjusted PPNR up 20% Revenue $(569.5)M $232.5M 9% ─ Net interest margin at 3.50%, up 44 bps 1 1 1 ─ Adjusted efficiency ratio improves 280 bps PPNR $(711.6)M $92.8M 20% ─ Total loans at $17.2B, up 2% on a linked quarter annualized basis ─ Deleveraging drives decline in total deposits while improving deposit mix and NIM 3.50% 44 bps costs ❑ Credit quality metrics remain sound NCO ratio 25 bps - ─ Net charge-offs at 25 bps; provision expense exceeded net charge-offs by $4.5M ─ ACL ratio ends 3Q25 at 1.50%, up 2 bps ACL ratio 1.50% 2 bps ❑ Strong capital position 1 ─ TCE ratio at 8.5%, up 7 bps linked quarter NPL/Loans 90 bps (2) bps ─ Total risk-based capital ratio at 15.1%, up 65 bps 1 TCE ratio 8.5% 7 bps Comparisons on this page are 3Q25 vs 2Q25, unless otherwise noted Bps = basis points LQ = linked quarter (3Q25 vs 2Q25) 4 LQ Change – represents 3Q25 results vs 2Q25 results (provided that for the Net Income, EPS, ROAA, Revenue, and PPNR lines, represents 3Q25 adjusted results vs 2Q25 adjusted results) 1 Non-GAAP measures that management believes aid in the discussion of results. See Appendix for Non-GAAP reconciliations

Run-rate performance exceeds balance sheet repositioning guidance across the board Repositioning Reported Sept-25 Commentary 4 3 Guidance 3Q25 Run-Rate ❑ 3Q results reflect a partial impact from balance sheet repositioning 1 ❑ Sept-25 run-rate outperforms initial guidance Net Interest Margin (FTE) 3.50% 3.50% 3.76% from balance sheet repositioning ❑ Expect 4Q25 NIM to be 3.65%+ Net Interest Income (% growth) 10% 9% 13% ▪ Assumes full impact of September rate cut and an additional 25 bps cut in October ▪ Continued positive fixed rate loan repricing ▪ Full quarter impact of hedging program 2 Pre-Provision Net Revenue (% growth) 21% 20% 25% 2 Adjusted ROAA 1.10% 1.03% 1.15% 2 Adjusted ROTCE 14.0% 13.6% 14.9% CET1 Ratio 11.5% 11.5% Total Risk-Based Capital Ratio 13.5% 15.1% Sustainable performance in all key financial metrics with upside potential from strategic initiatives 1 Net interest margin (NIM) is presented on a fully taxable equivalent (FTE) basis using an effective tax rate of 26.135% 2 Non-GAAP measures that management believes aid in the discussion of results. See appendix for Non-GAAP reconciliations 5 3 Sept-25 run rate reflects month of September results and is presented for informational purposes only. Percentage growth rates have been quarterized, are not guarantees of future performance, and may not reflect actual results for any full quarterly or annual period 4 Issued by the Company as of September 9, 2025, and not subsequently updated. Presented here for historical informational purposes only

Income Statement Highlights 2 2 Net Interest Income Adjusted Total Revenue Adjusted PPNR $ in millions $ in millions $ in millions $232.5 +9% $92.8 $186.7 +20% +9% $214.2 $77.3 $209.6 $208.5 $203.2 $171.8 $69.2 $66.4 $66.0 $164.9 $163.4 $157.7 3Q24 4Q24 1Q25 2Q25 3Q25 3Q24 4Q24 1Q25 2Q25 3Q25 3Q24 4Q24 1Q25 2Q25 3Q25 1 NIM 2.74% 3.06% 3.50% 2.87% 2.95% 2 2 2 Adjusted NIE Adjusted Net Income Adjusted Diluted EPS $ in millions $ in millions +5% +16% $64.9 $143.6 $0.46 $0.44 $56.1 $0.39 $139.7 $49.6 $0.37 $139.3 $46.0 $136.8 $136.8 $33.1 $0.26 3Q24 4Q24 1Q25 2Q25 3Q25 3Q24 4Q24 1Q25 2Q25 3Q25 3Q24 4Q24 1Q25 2Q25 3Q25 PPNR – Pre-provision net revenue NIE – Noninterest Expense 6 EPS – Earnings per Share 1 Net interest margin (NIM) is presented on a fully taxable equivalent (FTE) basis using an effective tax rate of 26.135% 2 Non-GAAP measures that management believes aid in the discussion of results. See appendix for Non-GAAP reconciliations

Net Interest Margin (FTE) 1 2 1 Net Interest Margin Deleveraging Evolution Net Interest Margin Evolution FTE (%) $ in billions; Average Balances FTE 2Q25 July-25 Aug-25 Sept-25 3 bps +76 bps 3.50% 4 bps 1 38 bps 3.06% 3.18% 3.62% 3.76% NIM (1) bps 3.50% $24.0 3.06% $20.0 26% 24% 3.06% 2.95% +44 bps 16% 16% 2.87% 2.74% $16.0 $12.0 Loan Funding 2Q25 BS Other 3Q25 Yield Rate 73% 74% 81% 82% Repositioning $8.0 3Q24 4Q24 1Q25 2Q25 3Q25 Balance … Funding Rate NIM - 4Q24 NIM - 4Q24 Loan Yield Other $4.0 $- Commentary (3Q25 vs 2Q25) $(4.0) Select Yields/Rates th ❑ 6 consecutive quarter of NIM expansion; 3Q25 NIM FTE (%) expansion primarily due to balance sheet repositioning $(8.0) 6.44 6.32 6.26 6.31 86% 87% 82% 6.20 81% 1 ❑ Expect 4Q25 NIM to be 3.65%+ $(12.0) ❑ Focused on maintaining loan pricing discipline and $(16.0) continued proactive deposit pricing management 4.01 3.63 3.54 3.48 3.48 ▪ 5 bps increase in loan yields 10% 12% $(20.0) 17%▪ 11 bps decrease in deposit costs 17% 3% ▪ Fixed-rate asset repricing remains a tailwind 2% 2.79 2.60 1% 2.44 $(24.0) 2.36 2% 2.25 ❑ Swap income of $7.5 million in 3Q25 compared to $8.1 3Q24 4Q24 1Q25 2Q25 3Q25 Customer deposits Wholesale funding Subordinated debt million in 2Q25 Loan Yield (FTE) Securities (FTE) Cost of Deposits Loans Securities Other earning assets 1 Net interest margin (NIM) is presented on a fully taxable equivalent (FTE) basis using an effective tax rate of 26.135% 2 Percentages in the NIM and Deleveraging Evolution graph represent average loans, securities and other earning assets as a percentage of total average earnings assets, and average customer deposits, and wholesale funding (brokered deposits and FHLB/other borrowings) as a 7 percentage of average interest bearing liabilities FTE – Fully taxable equivalent using an effective tax rate of 26.135% BS – Balance Sheet

Noninterest Income 3Q25 Adjusted 3Q25 vs Adjusted 1 $ in millions 2Q25 3Q24 Reported Adjusted Commentary Service charges on deposit accounts $ 13.0 $ 13.0 $ 0.5 4 % $ 0.3 3 % ❑ Continued focus on driving growth along major fee-based businesses results in 3Q25 fee Wealth management fees 10.0 10.0 0. 5 5 0.9 10 income at top end of management expectations Debit and credit card fees 8.5 8.5 ( 0.1) ( 1) 0.3 4 ❑ Increase in service charges on deposit accounts Mortgage lending income 2.3 2.3 0. 6 34 0.3 15 reflects growth in consumer accounts and performance in commercial treasury Bank owned life insurance 3. 9 3.9 0. 1 1 0.2 5 management Swap fee income 0.9 0.9 0. 1 9 0.2 24 ❑ Linked quarter increase in “Other” noninterest income primarily driven by negative SBIC Other service charges and fees 1. 5 1.5 0. 2 12 - (2) valuation adjustments in 2Q25 Other 5.2 5.8 1.8 45 (1.8) (24) ❑ Sold ~$2.4 billion of securities (fair value) for a pre-tax loss of ~$801.5 million or ~$626 million 45.3 45.9 3.5 8 0.4 1 after-tax loss Gain (loss) on sale of securities (pre-tax) (801.5) - - - - - Total noninterest income $(756.2) $ 45.9 $ 3.5 8 % $ 0.4 1 % 1 Adjusted Total Revenue Per Employee Adjusted Noninterest Income Adjusted PPNR per Avg. Diluted Share 1 1 (FTE) to Adjusted Total Revenue ($ in thousands) +8% $0.66 22.4% $80.7 22.0% $0.61 20.9% $72.7 $71.1 19.7% $70.8 19.8% $68.4 $0.55 $0.53 $0.52 3Q24 4Q24 1Q25 2Q25 3Q25 3Q24 4Q24 1Q25 2Q25 3Q25 3Q24 4Q24 1Q25 2Q25 3Q25 Totals may not foot due to rounding FTE – Full-time equivalent 8 1 Non-GAAP measures that management believes aid in the discussion of results. See appendix for Non-GAAP reconciliations

Noninterest Expense 3Q25 Adjusted 3Q25 vs Adjusted Commentary 1 $ in millions Reported 2Q25 3Q24 Adjusted ❑ 3Q25 noninterest expense at top end of management expectations Salaries and employee benefits $ 76.2 $ 75.9 $ 3.7 5 % $ 6.8 10 % ▪ Full-year expenses projected to beat previously issued Occupancy expense, net 12.1 1 1.7 0.2 2 ( 0.3) (3) 2% growth guidance while absorbing 1Q25 fraud event Furniture and equipment 5.3 5.3 (0.2) ( 4) (0.4) (6) ❑ Linked quarter increase in salaries and employee benefits primarily reflects YTD accrual true-ups Deposit insurance 5.2 5.2 0.3 5 (0.4) (7) ❑ “Other” noninterest expense improved linked OREO and foreclosure expense 0.2 0.2 - ( 7) 0.1 130 quarter due to $1.6 million fraud recovery in 3Q25 Other 43.0 41.5 ( 1.1) ( 2) (2.9) (7) ❑ Adjusted efficiency ratio improves 280 bps on a linked quarter basis Total noninterest expense $142.0 $139.7 $ 2.9 2 % $ 2.9 2 % 1 Adjusted Efficiency Ratio Employees (FTE) # of Financial Centers 280 bps 234 2,972 64.75% 2,949 2,947 improvement 2,946 63.38% 62.89% 2,883 223 223 222 222 60.52% 57.72% 3Q24 4Q24 1Q25 2Q25 3Q25 3Q24 4Q24 1Q25 2Q25 3Q25 3Q24 4Q24 1Q25 2Q25 3Q25 Note: Numbers may not add due to rounding FTE – full-time equivalent 9 1 Non-GAAP measures that management believes aid in the discussion of results. See appendix for Non-GAAP reconciliations

Deposits, Securities, Liquidity, Interest Rate Sensitivity and Capital 10

Deposits Decline in total deposits reflects reduction of higher Deposit Mix As a Percentage of Total Deposits rate, non-relationship wholesale and public fund $ in billions; Period End Balances Period End Balances 2Q25 3Q25 deposits as part of balance sheet repositioning $21.9 $21.9 $21.7 $21.8 Noninterest bearing 20.5% 22.1% $19.8 $3.4 $3.3 $2.9 $3.2 $1.8 $2.7 $2.8 $3.0 $2.7 $2.2 Interest bearing transaction accounts 39.0% 42.8% $2.9 $2.9 $3.3 $3.1 $3.0 Time deposits 13.4% 14.7% $8.5 $8.0 $8.2 $8.3 $8.5 $4.5 $4.5 $4.5 $4.5 $4.4 Public funds (interest bearing) 12.3% 11.1% 3Q24 4Q24 1Q25 2Q25 3Q25 Noninterest Bearing Interest Bearing Transaction Accounts Time Deposits Public Funds (interest bearing) Brokered Deposits Customer deposits 85.2% 90.7% 65% interest bearing Evolution of Funding Rates 1 deposit beta since 2Q24 Brokered deposits 14.8% 9.3% Interest Bearing Deposits Cost of Deposits 5.33% 5.33% 5.33% 5.26% 5.27% Avg Fed Funds Rate 4.99% 4.66% 4.52% 4.33% 4.33% 4.30% Commentary 3.65% 3.53% 3.52% 3.48% 3.31% 3.28% 3.06% 3.05%❑ Balance sheet repositioning results in improved mix of deposits 2.97% 2.86% 2.57% 2.10%▪ Noninterest bearing deposits represent 22.1% of total deposits 2.79% 2.79% 2.75% ▪ Lower cost interest bearing transaction accounts represent 42.8% of total deposits 2.58% 2.60% 1.41% 2.44% 2.37% 2.36% 2.25% 1.96% ❑ 11 basis point decrease in cost of deposits on a linked quarter basis 1.58% 1.02% ❑ Focus remains on optimizing deposit balances and proactively managing costs 2Q22 3Q22 4Q22 1Q23 2Q23 3Q23 4Q23 1Q24 2Q24 3Q24 4Q24 1Q25 2Q25 3Q25 ❑ ~77% of deposits are FDIC insured or are collateralized deposits Source: Average Fed Funds rate based on data from www.macrotrends.net 1 Deposit beta calculated as change in cost of deposits from 2Q24 to 3Q25 divided by the change in quarterly average Federal Funds Effective rate for 2Q24 vs 3Q25 11

Securities and Liquidity 2 Securities Portfolio Summary Securities Portfolio Bond Ratings Securities Portfolio by Type $ in millions 5% 2% 1 Yield (FTE) Effective Duration At September 30, 2025 At September 30, 2025 AFS 25% AFS AFS Fixed Rate U.S. Guaranteed/GSE $2,508 Municipal 3.34% 13.02 Aaa/AAA 406 MBS/CMO 2.61 5.33 Aa/AA 656 Treasury/Agency 3.71 0.64 A 88 Corporate 5.97 0.97 Baa/BBB 133 Other 2.46 8.29 68% Not Rated 10 Variable Rate 4.68 - Treasury/Agency States and Political Subdivisions Total $3,801 MBS/CMO Corporate & Other Total 3.23% 6.31 Additional Liquidity Sources Wholesale Funding $ in millions $ in millions September 30, Change vs FHLB borrowing availability $ 6,134 2025 2Q25 Unpledged securities 1,575 Brokered deposits $1,841 $(1,396) Fed Funds lines and Fed Discount Window 1,824 FF purchased/securities sold 22 (9) FHLB advances 3 (615) Other 16 - Total at 9.30.25 $9,533 Total $1,882 $(2,020) 3 Uninsured, non-collateralized deposits $4,459 Wholesale Funding / Total Funding = 9.5% Coverage ratio 2.1x FTE – fully taxable equivalent using an effective tax rate of 26.135% Data presented on this slide is as of September 30, 2025, unless otherwise noted 12 1 Effective yield of securities portfolio at 9/30/25 2 Bond ratings reflect highest rating by Moody's Investors Service, Inc., Standard & Poor's or Fitch Ratings 3 Uninsured, non-collateralized deposits represent uninsured deposits of Simmons Bank, less the uninsured portion of collateralized deposits, and deposit balances of SFNC subsidiaries. See appendix for Non-GAAP reconciliations

Interest Rate Sensitivity Loan Portfolio – Repricing and Maturity (contractual) CD Maturities (over the next 12 months) At September 30, 2025 $ in millions In millions Repricing Term Rate Structure Weighted Average Rates 3 mo 3-12 1-3 3-5 Over 5 Total Variable Fixed 3.72% 4.36% 3.58% 4.12% 3.30% 4.24% 3.04% or less mo years years years RE - Construction $ 2,412.5 $ 143.7 $ 235.8 $ 73.8 $ 9.0 $ 2,874.8 $ 2,316.4 $ 558.4 RE - Commercial 3,158.3 912.7 2,477.6 707.2 619.9 7,875.7 3,349.9 4,525.8 $1,455.3 RE - Single-Family 634.2 287.4 597.1 394.3 704.8 2,617.8 1,429.5 1,188.3 $1,001.9 $830.9 Commercial 1,535.8 96.1 399.8 260.2 105.4 2,397.4 1,573.2 824.2 $337.4 Consumer 215.0 11.9 40.3 10.1 8.0 285.4 207.4 78.0 $264.6 $214.6 $101.3 1 Other 733.7 32.3 48.0 41.1 282.8 1,137.8 723.3 414.5 4Q25 1Q26 2Q26 3Q26 Total $ 8,689.5 $ 1,484.1 $ 3,798.6 $ 1,486.7 $ 1,729.9 $ 17,188.8 $ 9,599.7 $ 7,589.1 Customer CDs Brokered CDs 2 7.16% 5.34% 5.46% 6.16% 4.69% 6.26% 6.95% 5.44% Weighted average rate Note: Weighted average rates in the table above are based on contractual repricing and maturity. Does not include the impact of Hedging Program summarized on Slide 14 Balance Sheet Interest Rate Sensitivity Over the next 12 months (estimated) Additional Interest Rate Sensitivity Factors Change in Interest Rates % Impact on Net Interest Income 3 ❑ ~$100 million of projected securities principal maturities per quarter 4 ❑ ~$2.3 billion of projected cash flows from fixed rate loans at a weighted average rate of 5.75% Down 25 bps (0.5)% 5 ❑ ~29% of customer interest bearing deposits are tied to index rates, principally Fed Funds target rate Down 50 bps (0.9)% ❑ $1.625 billion Hedging Program summarized on slide 14 Down 75 bps (1.2)% Assumes a gradual change in interest rates and static balance sheet as of September 30, 2025. Interest rate cuts are assumed in October 2025, December 2025 and April 2026 Totals may not add due to rounding 1 Other includes agriculture, mortgage warehouse and other loans 13 2 Weighted average rates do not include mortgage warehouse and credit card portfolios 3 Projections over the next 12 months assuming a static balance sheet as of September 30, 2025 4 Cash flows from fixed rate loans over the next 12 months includes prepayment assumptions and are based on the forward rate curve 5 Customer interest bearing deposits includes savings, money market, checking and customer CDs. Does not include brokered deposits

Hedging Program 1 Estimated Future Swap Income Hedging Program Strategy $ in millions; Based on forward rates ❑ Net interest income (NII) sensitivity moved from liability sensitive to asset sensitive post balance sheet $6.2 restructure $5.7 $5.3 $5.1 $5.0 ❑ Evolved 3Q25 hedging strategy to protect NII from falling rates ❑ Executed $1.625 billion of interest rate swaps in 3Q25 to reduce negative impact of falling rates by ~50% resulting in near neutral IRR position ▪ Added $1.0 billion combination spot and forward starting receive fixed swaps to hedge variable rate loans ▪ Added $300 million combination spot and forward starting receive fixed swaps to hedge variable rate CMBS ▪ Added $325 million combination spot and forward starting receive fixed swaps to hedge recently issued fixed rate subordinated debt 4Q25 1Q26 2Q26 3Q26 4Q26 Quarterly Average (Notional) Annual Average (Notional) Hedged Item Quarter Initiated Rate Protection 3Q25 4Q25 1Q26 2Q26 3Q26 4Q26 2027 2028 2029 2030 Variable rate loans 3Q25 Down rate $ 573.4 $ 1,000.0 $ 1,000.0 $ 1,000.0 $ 1,000.0 $ 1,000.0 $ 1,000.0 $ 899.6 $ 209.6 $ - Varibale rate CMBS 3Q25 Down rate 117.4 300.0 300.0 300.0 260.9 200.0 130.4 - - - Subordinated debt 3Q25 Down rate 67.1 325.0 325.0 325.0 325.0 325.0 325.0 325.0 325.0 244.0 Fixed rate munis 3Q21 Up rate 1,001.7 1,001.7 1,001.7 1,001.7 1,001.7 1,001.7 1,001.7 937.2 54.2 - Net Asset Swap Position (up rate - down rate) $ ( 243.8) $ 623.3 $ 623.3 $ 623.3 $ 584.2 $ 523.3 $ 453.7 $ 287.4 $ 480.4 $ 244.0 Quarterly Fixed Rate Annual Fixed Rate Hedged Item Receive Pay 3Q25 4Q25 1Q26 2Q26 3Q26 4Q26 2027 2028 2029 2030 Variable rate loans Fixed 1M SOFR 4.03% 4.03% 3.59% 3.24% 3.24% 3.24% 3.24% 3.26% 3.22% - Varibale rate CMBS Fixed 1M SOFR 3.82% 3.82% 3.82% 3.82% 3.53% 3.07% 3.07% - - - Subordinated debt Fixed SOFR 30D average 3.56% 3.56% 3.56% 3.56% 3.56% 3.07% 3.07% 3.07% 3.07% 3.07% Fixed rate munis Fed effective Fixed 1.21% 1.21% 1.21% 1.21% 1.21% 1.21% 1.21% 1.22% 1.22% - Totals may not add due to rounding 1 Estimated swap income based on projected forward effective fed funds rates as of September 30, 2025. Does not include potential impact of hedge ineffectiveness that is recorded in interest income. 14

3 Capital: Economic Capital improves across the board following balance sheet repositioning 1 1 CET 1 Capital Ratio Tier 1 Leverage Ratio 12.4% 10.0% 11.5% 9.6% Capital Ratios (at 9/30/25) 9.9% 8.2% CET 1 Capital Ratio Total Risk-Based Capital Ratio Adj. HTM Reported 15.1% 2,3 11.5% Loss 2 Equity to Assets Tangible Common Equity Ratio 2Q25 3Q25 13.9% 8.5% 2Q25 3Q25 WELL CAPITALIZED WELL CAPITALIZED 5.0% 6.5% 1 1 Total Risk-Based Capital Ratio Tier 1 Risk-Based Capital Ratio Subordinated Debt 15.1% $37M of subordinated debt due 2030 redeemed and paid in full on July 31, 2025 14.4% 12.4% 11.5% $330M of subordinated debt due 2028 redeemed and paid in full on October 1, 2025 12.0% 9.9% $325M of subordinated debt due 2035 issued during 3Q25. See slide 14 for more information on the hedging instrument that converts the debt from fixed rate to floating rate Current Term/Structure Maturity Date Call Date Amount Coupon 10 yr NC 5 10/1/2035 10/1/2030 $325M 6.25% 2Q25 3Q25 2Q25 3Q25 WELL CAPITALIZED WELL CAPITALIZED 8.0% 10.0% 1 3Q25 data as of September 30, 2025, 2Q25 data as of June 30, 2025, and 3Q24 data as of September 30, 2024 2 Non-GAAP measures that management believes aid in the discussion of results. See Appendix for Non-GAAP reconciliations 15 3 Economic Capital Inclusive of after-tax loss from transfer of HTM portfolio to AFS of ~$501 million

Loan Portfolio 16

Loans: Well-diversified, granular portfolio and conservative credit culture Loan Portfolio Waterfall Linked Quarter Change by Loan Type $ in millions $ in millions Total Loans $78 $2,113 RE – Commercial $(85) $136 $17,189 $17,111 RE – Construction $(2,171) $90 1 Funded loans Paydowns/ Other 2 Commercial $(39) /advances payoffs RE – Single Family $(8) Consumer & Other $(16) Agricultural $20 Mortgage Warehouse $120 Total loans Total loans 3 Run-Off Portfolio $(4) at 6/30/25 at 9/30/25 Unfunded Commitments $ in millions Commentary RE - Construction Commercial RE - Single Family RE - Commercial Agriculture Consumer/Other ❑ Well-diversified, granular portfolio with no significant industry or geographic concentrations $3,947 $3,888 $3,955 $3,739 $3,681 ❑ Total loans at $17.2 billion, up 2% on a linked quarter annualized basis 94% variable rate❑ Unfunded commitments increased for 4th consecutive quarter • 62% tied to Prime ❑ Minimal exposure to Shared National Credits (SNC) • 38% tied to SOFR ▪ SNC totaled ~1% of total loans ▪ Additional banking relationships with all borrowers 3Q24 4Q24 1Q25 2Q25 3Q25 1 “Other” includes linked quarter change associated with loan portfolios impacted by seasonality (agricultural, mortgage warehouse and credit cards) and change in run-off portfolio 2 Commercial loan change excludes the impact of loans included in the run-off portfolio 17 3 “Run-off portfolio” consists of small ticket equipment finance and acquired asset based lending portfolios

Pipelines: Represent opportunities that meet disciplined appetite for credit and pricing Commercial Loan Pipeline by Category $ in millions Opportunity Proposal Ready to Close $1,815 $1,631 $1,611 Commentary $757 $1,265 $490 ❑ Continued focus on maintaining prudent underwriting $1,244 $564 standards and pricing discipline $1,013 $1,002 $552 $549 ❑ $490 million of ready to close loans in the commercial $249 $292 $436 1 $330 $381 pipeline as of September 30, 2025, with a rate of 7.19% $121 $168 $199 $147 ❑ Mortgage loan originations in 3Q25 ❑ 80% purchase ❑ 20% refinance $485 $551 $527 $514 $809 $775 $685 1Q24 2Q24 3Q24 4Q24 1Q25 2Q25 3Q25 Rate Ready to 8.38% 8.68% 8.31% 7.93% 7.39% 7.35% 7.19% 1 Close Mortgage Loan Volume $ in millions Mortgage Closed Loan Volume Mortgage Pipeline Volume $31 $25 $27 $27 $29 $32 $16 $111 $110 $96 $89 $78 $75 $69 1Q24 2Q24 3Q24 4Q24 1Q25 2Q25 3Q25 1 Rate ready to close represents the weighted average rate on commercial loans that are ready to close and does not include fees, including FAS 91 fees, associated with those commercial loans 18

Loans: Conservative LTVs underpin prudent underwriting standards in key sectors Office (non-owner occupied permanent) Key Statistics At 9/30/25 Loan Portfolio – Geographic diversification By State By State NPL Ratio 0.00% 16% Past Due 30+ Days 0.00% 2% 2% 20% Average Loan Size $2.2M 46% 33% 8% Median Loan Size $0.5M $0.7B 2% Number of Loans <$1M 63% 13% 4% 1 Average LTV 46.7% $16.6B 13% Weighted Average LTV 54.4% 9% Texas Arkansas Tennessee Missouri Oklahoma Kansas Other Multifamily (permanent) Key Statistics At 9/30/25 19% 13% By State 11% NPL Ratio 0.87% Texas Arkansas Tennessee Missouri 10% 38% Past Due 30+ Days 0.00% Oklahoma Kansas Other 5% Average Loan Size $3.0M $0.9B 5% Median Loan Size $0.6M % of Total % of Total Top 10 MSAs Number of Loans <$1M 65% 1 1 Loans Commitments 14% 17% Average LTV 51.3% Dallas-Plano-Irving 9.3% 9.1% Texas Arkansas Tennessee Missouri Oklahoma Kansas Other Weighted Average LTV 61.0% Houston-Sugarland-Baytown 9.2% 8.7% Little Rock-North Little Rock-Conway 6.0% 6.7% Retail (non-owner occupied permanent) Key Statistics At 9/30/25 Nashville-Davidson-Murfreesboro 4.9% 5.6% By State NPL Ratio 0.20% 15% Memphis 4.8% 4.7% 1% Past Due 30+ Days 0.02% Fort Worth-Arlington 4.0% 4.0% 5% 47% Average Loan Size $1.8M Fayetteville-Springdale-Rogers 3.3% 3.1% 7% $0.9B Median Loan Size $1.0M St. Louis 2.6% 2.4% Number of Loans <$1M 51% 10% Kansas City 2.2% 2.5% Average LTV 47.8% Jonesboro 2.2% 2.0% 15% Weighted Average LTV 55.5% Texas Arkansas Tennessee Missouri Oklahoma Kansas Other Data shown above as of September 30, 2025 1 Total loans or commitments excluding credit card portfolio and mortgage warehouse 19

CLD: Quick recycling of capital given short duration of portfolio Construction and Land Development (CLD) By State % of Total % of Total Key Statistics At 9/30/25 Top 10 MSAs Loans Commitments NPL Ratio 0.32% Dallas-Plano-Irving 10.6% 10.7% Past Due 30+ Days 0.01% 27% Nashville-Davidson-Murfreesboro 9.0% 10.1% 43% Average Loan Size $1.4M Houston-Sugarland-Baytown 8.7% 8.3% Median Loan Size $0.3M Memphis 6.1% 5.3% $2.9B Number of Loans <$1M 83% 2% Little Rock-North Little Rock-Conway 5.6% 4.9% 2% Average LTV 56.0% Fort Worth-Arlington 4.1% 4.4% 4% Weighted Average LTV 52.7% Corpus Christi 3.0% 2.5% Weighted Average Maturity ~20 months 13% 9% Fayetteville-Springdale-Rogers 2.7% 2.6% Texas Arkansas Tennessee Missouri Orlando-Kissimmee-Sanford 2.5% 2.6% Oklahoma Kansas Other Phoenix-Mesa-Glendale 1.7% 3.8% CLD - Industrial Warehouse (non-owner occupied) CLD - Multifamily By State By State Key Statistics At 9/30/25 Key Statistics At 9/30/25 NPL Ratio 0.00% 14% NPL Ratio 0.00% Texas 24% Texas Past Due 30+ Days 0.00% Past Due 30+ Days 0.00% 44% Arkansas Tennessee 17% 45% Average Loan Size $19.1M Average Loan Size $11.9M Tennessee Missouri $0.8B $0.6B Median Loan Size $19.1M 5% Median Loan Size $7.6M Kansas Florida 5% Number of Loans <$1M 26% Number of Loans <$1M 35% Florida Other 6% Average LTV 48.1% 17% Average LTV 37.5% Other 7% 16% Weighted Average LTV 49.1% Weighted Average LTV 43.9% Weighted Average Maturity ~14 months Weighted Average Maturity ~12 months Data shown above as of September 30, 2025 20

Loans: Loan portfolio by type and key credit metrics as of June 30, 2025 as of September 30, 2025 % of % of Past Due 30+ Unfunded Unfunded Balance Total Balance Total Days Classified Nonperforming Commitment ACL Commitment $ in millions $ Loans $ Loans $ $ $ $ % Reserve Total Loan Portfolio Credit Card 176 1% 173 1% 2 1 1 - 3.46% - Consumer – Other 124 1% 112 1% 1 - - 32 3.11% 0.76% Real Estate – Construction 2,785 16% 2,875 17% - 12 9 1,826 1.45% 1.05% Real Estate – Commercial 7,961 47% 7,876 46% 2 336 81 302 1.58% 0.37% Real Estate - Single-family 2,626 15% 2,618 15% 12 37 31 308 1.61% 0.88% Commercial 2,440 14% 2,397 14% 3 52 30 1,373 1.45% 0.16% Mortgage Warehouse 324 2% 444 2% - - - - 0.20% - Agriculture 333 2% 353 2% - 2 1 114 0.61% 0.13% Other 342 2% 341 2% - 1 1 - 0.75% 5.74% Total Loan Portfolio 17,111 100% 17,189 100% 20 441 154 3,955 1.50% 0.65% Loan Concentration (Holding Company Level) C&D 94% 96% CRE 268% 268% Select Loan Categories Retail 1,164 7% 1,158 7% - 4 2 110 0.99% 0.76% Nursing / Extended Care 231 1% 229 1% 1 108 - 1 7.48% 0.03% Healthcare 586 3% 554 3% - 21 3 98 1.21% 0.14% Multifamily 1,852 11% 1,734 10% - 33 8 490 1.33% 0.25% Hotel 698 4% 697 4% - 60 27 158 3.79% 1.58% Restaurant 603 4% 611 4% - 36 28 26 3.60% 0.46% NOO Office 782 5% 808 5% - 20 8 106 2.43% 0.82% NOO Industrial Warehouse 1,371 8% 1,444 8% - 19 - 400 0.34% 0.14% 1 Run-Off Portfolio 47 <1% 43 <1% 1 4 3 1 6.50% - 1 “Run-off portfolio” consists of small ticket equipment finance and acquired asset based lending portfolios 21

Credit Quality 22

Credit Quality: Nonperforming and past due loans Nonperforming Loans Nonperforming Loans Evolution $ in millions $ in millions $157.2 $153.9 $152.4 $3.9 $49.6 $49.3 $49.8 $157.2 $110.8 $101.7 $(3.5) $5.5 $(0.7) $0.6 $3.5 $153.9 $3.3 $3.8 $7.4 $(0.2) $(3.1) $(0.3) $105.3 $104.1 $101.3 $98.8 $94.3 RE – Run-Off Two Specific 2Q25 RE - RE - Commercial Consumer & 3Q25 3Q24 4Q24 1Q25 2Q25 3Q25 3 1 Construction Commercial Single Family Other Portfolio Credit 2 Core Portfolio Run-Off Portfolio1 Two Specific Credit Relationships2 Relationships 4 4 4 Past Due 30-89 days / Total Loans Nonperforming Loans / Total Loans Nonperforming Assets / Total Assets Strategic decision to de-risk certain elements of the loan portfolio through the planned exit of particular acquired non- relationship credits Annual Annual Quarterly Annual Quarterly Quarterly 0.96% 0.66% 0.92% 0.64% 0.90% 0.89% 0.62% 0.61% 0.55% 0.65% 0.65% 0.45% 0.45% 0.59% 0.57% 0.38% 0.50% 0.33% 0.65% 0.31% 0.44% 0.63% 0.46% 0.42% 0.60% 0.61% 0.24% 0.22% 0.21% 0.24% 0.22% 0.21% 0.20% 0.17% 0.37% 0.11% 0.11% 0.23% 0.18% NPL Ratio NPL Ratio, excluding Two Specific Credit Relationships5 NPA to Assets NPA to Assets, excluding Two Specific Credit Relationships5 2019 2020 2021 2022 2023 2024 3Q24 4Q24 1Q25 2Q25 3Q25 2019 2020 2021 2022 2023 2024 3Q24 4Q24 1Q25 2Q25 3Q25 2019 2020 2021 2022 2023 2024 3Q24 4Q24 1Q25 2Q25 3Q25 Source: S&P Global Market Intelligence 2019 – 2024; Company Reports 1 “Run-off portfolio” consists of small ticket equipment finance and acquired asset based lending portfolios 2 For purposes of the slides in this presentation, “Two Specific Credit Relationships” refers to the two largest nonperforming loans as of September 30, 2025 3 Consumer & Other includes credit card, consumer-other, mortgage warehouse, agriculture and other loan portfolios 23 4 As of December 31, for each respective year shown above; quarterly data as of the end of the quarter for each respective period 5 Non-GAAP measures that management believes aid in the discussion of results. See appendix for Non-GAAP reconciliations

ACL: Loan loss provision and net charge-offs Loan Loss Provision and Net Charge-Off Ratio Credit Quality Commentary $ in millions $40.0 0.40% ❑ Underlying credit metrics remain healthy 0.27% 0.25% ▪ 11 bps of loans past due 30-89 days, down 6 bps from 2Q25 levels 0.30% 0.25% $35.0 0.23% 0.22% 1 ▪ 61 bps NPL ratio excluding Two Specific Credit Relationships 0.20% $30.0 $26.8 ▪ Two Specific Credit Relationships represent 54% of our Top 10 NPLs 0.10% $25.0 0.00% ❑ NCO ratio of 25 bps in 3Q25; provision expense exceeded net charge-offs $20.0 $15.0 ❑ ACL to total loans ended 3Q25 at 1.50%, up from 1.48% at 2Q25 -0.10% $15.2 $15.0 $13.3 $12.1 $11.9 -0.20% $4.5 $1.8 $1.4 $2.8 $2.2 $10.0 ACL METHODOLOGY AS OF 9/30/25 -0.30% ▪ Moody’s Sept 2025 scenarios with management’s weighting: $11.5 $5.0 $10.6 $10.7 $9.3 $9.6 -0.40% Baseline (75%) / S1 (15%) / S3 (10%) ▪ Total credit coverage / total commitments: 1.34% $0.0 -0.50% 3Q24 4Q24 1Q25 2Q25 3Q25 ACL and ACL to Total Loans NCO Provision Incremental Provision Provision attributable to Two Specific Credit Relationships NCO Ratio $ in millions 1.75% $275.0 1.50% 1.48% 1.48% 1.55% 1.38% 1.35% 1.35% $250.0 $258.0 $253.5 $252.2 1.15% Reserve for Unfunded Commitments $235.0 $225.0 $233.2 0.95% As of As of As of As of As of $ in millions 9/30/24 12/31/24 3/31/25 6/30/25 9/30/25 0.75% $200.0 Unfunded Commitments $3,681 $3,739 $3,888 $3,947 $3,955 0.55% Reserve for Unfunded Commitments $25.6 $25.6 $25.6 $25.6 $25.6 0.35% $175.0 0.15% Provision for Unfunded Commitments - - - - - $150.0 -0.05% Reserve / Unfunded Balance 0.70% 0.69% 0.66% 0.65% 0.65% 3Q24 4Q24 1Q25 2Q25 3Q25 ACL ACL to Total Loans 1 Non-GAAP measures that management believes aid in the discussion of results. See appendix for Non-GAAP reconciliations 24

Forward-Looking Statements and Non-GAAP Financial Measures Forward-Looking Statements. Certain statements by Simmons First National Corporation (the “Company”, which where appropriate includes the Company’s wholly-owned banking subsidiary, Simmons Bank) contained in this presentation may not be based on historical facts and should be considered forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These forward-looking statements may be identified by reference to a future period(s) or by the use of forward-looking terminology, such as anticipate, “believe,” “continue,” estimate, expect, foresee,“ “indicate,” “plan,” “potential,” “project,” “target,” may, might, will, would, could,“ “should,” “likely” or intend, future or conditional verb tenses, and variations or negatives of such terms or by similar expressions. These forward-looking statements include, without limitation, statements relating to the Company’s future growth; business strategies; product development; revenue; expenses (including interest expense and non-interest expenses); assets; loan demand (including loan growth, loan capacity, and other lending activity); deposit levels; dividends; asset quality; profitability; earnings; critical accounting policies; net interest margin; noninterest income; the Company's common stock repurchase program; adequacy of the allowance for credit losses; income tax deductions; credit quality; level of credit losses from lending commitments; interest rate sensitivity (including, among other things, the potential impact of rising rates); loan loss experience; liquidity; capital resources; future economic conditions and market risk; interest rates; the Company’s securities portfolio; legal and regulatory limitations and compliance and competition; anticipated loan principal reductions; projections regarding loan repricing; the quarterized results for September 2025 set forth on slide 5; the net interest margin projection set forth on slides 5 and 7; the full-year expense commentary set forth on slide 9; the interest rate sensitivity estimates and projections set forth on slide 13; and the estimates related to the hedging program (including estimated future swap income) set forth on slide 14. Readers are cautioned not to place undue reliance on the forward-looking statements contained in this presentation in that actual results could differ materially from those indicated in or implied by such forward-looking statements due to a variety of factors. These factors include, but are not limited to, changes in the Company's operating or expansion strategy; the availability of and costs associated with obtaining adequate and timely sources of liquidity; changes in credit quality; changes in general market and economic conditions; increased unemployment; labor shortages; possible adverse rulings, judgments, fines, settlements and other outcomes of pending or future litigation; the ability of the Company to collect amounts due under loan agreements; significant increases in nonaccrual loan balances; changes in consumer preferences and loan demand; the effectiveness of the Company's interest rate risk management strategies; laws and regulations affecting financial institutions in general or relating to taxes; the effect of pending or future legislation; changes in governmental administrations; the ability of the Company to repurchase its common stock on favorable terms; the ability of the Company to successfully manage and implement its acquisition strategy and integrate acquired institutions; changes in tariff policies; difficulties and delays in integrating an acquired business or fully realizing cost savings and other benefits of mergers and acquisitions; changes in interest rates, deposit flows, real estate values, and capital markets; increased inflation; customer acceptance of the Company's products and services and changes in customer behaviors; changes or disruptions in technology and IT systems (including cyber or other information technology threats, attacks and events); changes in accounting principles relating to loan loss recognition (current expected credit losses, or CECL); fraud that results in material losses or that we have not discovered yet that may result in material losses; the benefits associated with the Company’s early retirement program; pandemics or significant health hazards, severe weather conditions, natural disasters, terrorist activities, political crises, war, and other military conflicts (including the ongoing military conflicts between Russia and Ukraine) or other major events, or the prospect of these events; increased competition in the markets in which the Company operates and from non-bank financial institutions; changes in governmental policies; the effects of a government shutdown; loss of key employees; reliance on third parties for key services; the soundness of other financial institutions and any indirect exposure related to the closings of other financial institutions and their impact on the broader market through other customers, suppliers and partners, or that the conditions which resulted in the liquidity concerns experienced by closed financial institutions may also adversely impact, directly or indirectly, other financial institutions and market participants with which the Company has commercial or deposit relationships; increased delinquency and foreclosure rates on commercial real estate and other loans; and other risk factors. Other relevant risk factors are detailed in the Company’s Form 10-K for the year ended December 31, 2024, the Company’s Form 10-Q for the quarter ended June 30, 2025, and other reports that the Company has filed with or furnished to the U.S. Securities and Exchange Commission (the SEC), all of which are available from the SEC on its website, www.sec.gov. In addition, there can be no guarantee that the board of directors (“Board”) of the Company will approve a quarterly dividend in future quarters, and the timing, payment, and amount of future dividends (if any) is subject to, among other things, the discretion of the Board and may differ significantly from past dividends. Any forward-looking statement speaks only as of the date of this presentation, and the Company undertakes no obligation to update these forward-looking statements to reflect events or circumstances that occur after the date of this presentation. Annualized, quarterized, pro forma, projected and estimated numbers are used for illustrative purpose only, are based on hypothetical assumptions that may not accurately reflect future incomes, are not forecasts and are not guaranteed and may differ significantly from actual results. Non-GAAP Financial Measures. This presentation contains financial information determined by methods other than in accordance with U.S. generally accepted accounting principles (“GAAP”). The Company’s management uses these non-GAAP financial measures in their analysis of the Company’s performance and capital adequacy. These measures adjust GAAP performance measures to, among other things, include the tax benefit associated with revenue items that are tax-exempt, as well as exclude from net income (including on a per share diluted basis), pre-tax, pre-provision earnings, net charge-offs, income available to common shareholders, non-interest income, and non-interest expense certain income and expense items attributable to, for example, loss on sale of securities, net branch right-sizing initiatives, early retirement program, termination of vendor and software services, and losses on early extinguishment of debt. In addition, the Company also presents certain figures based on tangible common stockholders’ equity, tangible assets and tangible book value, which exclude goodwill and other intangible assets, and presents certain other figures to include the effect that accumulated other comprehensive income could have on the Company’s capital levels. The Company further presents certain figures that are exclusive of the impact of deposits and/or loans acquired through acquisitions, mortgage warehouse loans, and/or energy loans, gains and/or losses on the sale of securities, or the Two Specific Credit Relationships. The Company’s management believes that these non-GAAP financial measures are useful to investors because they, among other things, present the results of the Company’s ongoing operations without the effect of mergers or other items not central to the Company’s ongoing business, present the Company’s capital inclusive of the potential impact of AOCI (primarily comprised of unrealized losses on securities), as well as normalize for tax effects and certain other effects. Management, therefore, believes presentations of these non-GAAP financial measures provide useful supplemental information that is essential to a proper understanding of the operating results of the Company’s ongoing businesses, and management uses these non-GAAP financial measures to assess the performance of the Company’s ongoing businesses as related to prior financial periods. These non-GAAP disclosures should not be viewed as a substitute for operating results determined in accordance with GAAP, nor are they necessarily comparable to non-GAAP performance measures that may be presented by other companies. Where non-GAAP financial measures are used, the comparable GAAP financial measure, as well as the reconciliation to the comparable GAAP financial measure, can be found in the appendix to this presentation. 25

Appendix 26

Select Balance Sheet and Other Data 3Q25 vs 2Q25 3Q25 vs 3Q24 $ in millions, except per share data 3Q25 2Q25 3Q24 $ Change % Change $ Change % Change Period End Balances Total loans $17,188.8 $17,111.1 $17,336.0 $77.7 - % $(147.2) (1) % Investment securities 3,319.3 5,996.9 6,349.8 (2,677.6) (45) (3,030.5) (48) Total assets 24,208.2 26,693.6 27,269.4 ( 2,485.5) (9) (3,061.2) (11) Total deposits 1 9,837.7 21,825.0 2 1,935.4 (1,987.3) (9) (2,097.7) (10) Borrowed funds 692.4 1,032.0 1,463.2 ( 339.6) (33) ( 770.8) (53) Total stockholders' equity 3,354.0 3,549.2 3,528.8 (195.2) (6) (174.9) (5) Average Balances Total loans $16,976.2 $17,046.8 $17,208.2 $(70.6) - % $(231.9) (1) % Investment securities 3,994.4 6,047.8 6,444.5 (2,053.4) (34) (2,450.0) (38) Total assets 24,914.9 26,645.1 27,216.4 (1,730.2) (6) (2,301.5) (8) Total deposits 20,529.1 21,431.0 2 1,717.4 ( 901.9) (4) (1,188.3) (5) Borrowed funds 699.5 1,359.7 1,670.5 ( 660.2) (49) ( 971.0) (58) Total stockholders' equity 3,368.3 3,546.2 3,505.1 ( 177.9) (5) ( 136.8) (4) Select Other Data Equity to assets 13.85 % 13.30 % 12.94 % 1 8.53 8.46 8.15 Tangible common equity to tangible assets Book value per share $23.18 $28.17 $28.11 1 13.45 16.97 16.78 Tangible book value per share Allowance for credit losses to total loans 1.50 % 1.48 % 1.35 % Nonperforming loan coverage ratio 168 161 229 1 Non-GAAP measures that management believes aid in the discussion of results. See appendix for Non-GAAP reconciliations 27

Income Summary 3Q25 Adjusted 3Q25 vs Adjusted 1 $ in millions, except per share data 2Q25 3Q24 Reported Adjusted Net interest income $186.7 $186.7 $14.8 9 % $28.9 18 % Noninterest income (756.2) 45.9 3.5 8 0.4 1 Total revenue (569.5) 232.5 18.4 9 29.3 14 Noninterest expense 142.0 139.7 2.9 2 2.9 2 2 (711.6) 9 2.8 15.5 20 26.4 40 Pre-provision net revenue Provision for credit losses 1 2.0 12.0 - - ( 0.2) (1) Provision for income taxes (160.7) 1 5.9 6.6 71 7.6 92 Earnings ($562.8) $ 64.9 $8.9 16 % $18.9 41 % Diluted EPS $(4.00) $ 0.46 $0.02 5 % $0.09 24 % Totals may not foot due to rounding 1 Non-GAAP measures that management believes aid in the discussion of results. See appendix for Non-GAAP reconciliations 28 2 All pre-provision net revenue (PPNR) figures set forth in this row are Non-GAAP measures. See footnote 1 for more information

Non-GAAP Reconciliations 3Q 4Q 1Q 2Q 3Q $ in thousands, except per share data 2024 2024 2025 2025 2025 1 Calculation of Adjusted Earnings Net Income (Loss) $ 24,740 $ 48,319 $ 32,388 $ 54,773 $ (562,792) Certain items Branch right sizing, net 410 1,581 994 163 2,004 Loss (gain) on sale of securities 28,393 - - - 801,492 Early retirement program (1) 200 - 1,594 305 Loss on early extinguishment of debt - - - - 570 Termination of vendor and software services (13) - - - - Tax effect (7,524) (466) (260) (459) (176,649) Certain items, net of tax 21,265 1,315 734 1,298 627,722 Adjusted earnings (non-GAAP) $ 46,005 $ 49,634 $ 33,122 $ 56,071 $ 64,930 1 Calculation of Earnings and Adjusted Earnings per Diluted Share Earnings available to common shareholders $ 24,740 $ 48,319 $ 32,388 $ 54,773 $ (562,792) Diluted earnings per share $ 0.20 $ 0.38 $ 0.26 $ 0.43 $ (4.00) Adjusted earnings available to common shareholders (non-GAAP) $ 46,005 $ 49,634 $ 33,122 $ 56,071 $ 64,930 Adjusted diluted earnings per share (non-GAAP) $ 0.37 $ 0.39 $ 0.26 $ 0.44 $ 0.46 Average Diluted Shares Outstanding 125,999,269 126,232,084 126,336,557 126,406,453 140,648,704 1 In this presentation, “Adjusted Earnings” may also be referred to as “Adjusted Net Income” 29

Non-GAAP Reconciliations 3Q 4Q 1Q 2Q 3Q 2024 2024 2025 2025 2025 $ in thousands Calculation of Pre-Provision Net Revenue (PPNR) Net interest income $ 157,712 $ 164,942 $ 163,422 $ 171,824 $ 186,661 Noninterest income 17,130 43,558 46,155 42,354 (756,187) Less: Noninterest expense 137,193 141,117 144,580 138,589 142,032 Pre-Provision Net Revenue (PPNR) (non-GAAP) $ 37,649 $ 67,383 $ 64,997 $ 75,589 $ (711,558) Calculation of Adjusted Pre-Provision Net Revenue Pre-Provision Net Revenue (PPNR) (non-GAAP) $ 37,649 $ 67,383 $ 64,997 $ 75,589 $ (711,558) Plus: (Gain) loss on sale of securities 28,393 - - - 801,492 Plus: Branch right sizing costs, net 410 1,581 994 163 2,004 Plus: Early retirement program (1) 200 - 1,594 305 Plus: Loss on early extinguishment of debt - - - - 570 Plus: Termination of vendor and software services (13) - - - - Adjusted Pre-Provision Net Revenue (non-GAAP) $ 66,438 $ 69,164 $ 65,991 $ 77,346 $ 92,813 Calculation of PPNR and Adjusted PPNR Per Share Average Diluted Shares Outstanding 125,999,269 126,232,084 126,336,557 126,406,453 140,648,704 PPNR per Average Diluted Shares Outstanding $ 0.30 $ 0.53 $ 0.51 $ 0.60 $ (5.06) Adjusted PPNR per Average Diluted Shares Outstanding (non-GAAP) $ 0.53 $ 0.55 $ 0.52 $ 0.61 $ 0.66 Calculation of Book Value and Tangible Book Value per Share Total common stockholders' equity $ 3,528,833 $ 3,528,872 $ 3,531,485 $ 3,549,210 $ 3,353,963 Intangible assets: Goodwill (1,320,799) (1,320,799) (1,320,799) (1,320,799) (1,320,799) Other intangible assets (101,093) (97,242) (93,714) (90,617) (87,520) Total intangible assets (1,421,892) (1,418,041) (1,414,513) (1,411,416) (1,408,319) Tangible common stockholders' equity (non-GAAP) $ 2,106,941 $ 2,110,831 $ 2,116,972 $ 2,137,794 $ 1,945,644 Shares of common stock outstanding 125,554,598 125,651,540 125,926,822 125,996,248 144,703,075 Book value per common share $ 28.11 $ 28.08 $ 28.04 $ 28.17 $ 23.18 Tangible book value per common share (non-GAAP) $ 16.78 $ 16.80 $ 16.81 $ 16.97 $ 13.45 30

Non-GAAP Reconciliations 3Q 4Q 1Q 2Q 3Q 2024 2024 2025 2025 2025 $ in thousands, except number of employees (FTE) Calculation of Total Revenue and Adjusted Total Revenue Net Interest Income (GAAP) $ 157,712 $ 164,942 $ 163,422 $ 171,824 $ 186,661 Noninterest Income (GAAP) 17,130 43,558 46,155 42,354 (756,187) Total Revenue (non-GAAP) $ 174,842 $ 208,500 $ 209,577 $ 214,178 $ (569,526) Total Revenue (non-GAAP) $ 174,842 $ 208,500 $ 209,577 $ 214,178 $ (569,526) Less: Gain (loss) on sales of securities (28,393) - - - (801,492) Less: Loss on early extinguishment of debt - - - - (570) Adjusted Total Revenue (non-GAAP) $ 203,235 $ 208,500 $ 209,577 $ 214,178 $ 232,536 Employees (FTE) 2,972 2,946 2,949 2,947 2,883 Total Revenue per Employee (FTE) $ 58.83 $ 70.77 $ 71.07 $ 72.68 $ (197.55) Adjusted Total Revenue per Employee (FTE) $ 68.38 $ 70.77 $ 71.07 $ 72.68 $ 80.66 Calculation of Adjusted Noninterest Income Noninterest Income (GAAP) $ 17,130 $ 43,558 $ 46,155 $ 42,354 $ (756,187) Less: Gain (loss) on sale of securities (28,393) - - - (801,492) Less: Loss on early extinguishment of debt - - - - (570) Adjusted Noninterest Income (non-GAAP) $ 45,523 $ 43,558 $ 46,155 $ 42,354 $ 45,875 Calculation of Noninterest Income to Total Revenue Noninterest Income to Total Revenue 9.80% 20.89% 22.02% 19.78% NM Adjusted Noninterest Income to Adjusted Total Revenue (non-GAAP) 22.40% 20.89% 22.02% 19.78% 19.73% FTE – Full time equivalent NM – Not meaningful 31

Non-GAAP Reconciliations 3Q 4Q 1Q 2Q 3Q 2024 2024 2025 2025 2025 $ in thousands Calculation of Adjusted Noninterest Expense Noninterest Expense (GAAP) $ 137,193 $ 141,117 $ 144,580 $ 138,589 $ 142,032 Less: Branch right sizing expense 410 1,581 994 163 2,004 Less: Early retirement program (1) 200 - 1,594 305 Less: Termination of vendor and software services (13) - - - - Adjusted Noninterest Expense (non-GAAP) $ 136,797 $ 139,336 $ 143,586 $ 136,832 $ 139,723 Calculation of Efficiency Ratio and Adjusted Efficiency Ratio Noninterest Expense (efficiency ratio numerator) $ 137,193 $ 141,117 $ 144,580 $ 138,589 $ 142,032 Total Revenue $ 174,842 $ 208,500 $ 209,577 $ 214,178 $ (569,526) Fully taxable equivalent adjustment ___ _ _6,398 ___ _ _6,424 ___ _ _6,414 ___ _ _6,422 ___ _ _3,811 Efficiency ratio denominator $ 181,240 $ 214,924 $ 215,991 $ 220,600 $ (565,715) Efficiency ratio (based on GAAP figures) 75.70% 65.66% 66.94% 62.82% (25.11)% Adjusted Noninterest Expense (non-GAAP) $ 136,797 $ 139,336 $ 143,586 $ 136,832 $ 139,723 Less: Other real estate and foreclosure expense 87 317 198 216 200 Less: Amortization of intangible assets ___ __ 3,851 ___ __ 3,850 ___ __ 3,527 ___ __ 3,098 ___ __ 3,097 Adjusted efficiency ratio numerator (non-GAAP) $ 132,859 $ 135,169 $ 139,861 $ 133,518 $ 136,426 Adjusted Total Revenue (non-GAAP) (reconciliation shown on page 31) $ 203,235 $ 208,500 $ 209,577 $ 214,178 $ 232,536 Fully taxable equivalent adjustment ___ _ _6,398 ___ _ _6,424 ___ _ _6,414 ___ _ _6,422 ___ _ _3,811 Adjusted efficiency ratio denominator (non-GAAP) $ 209,633 $ 214,924 $ 215,991 $ 220,600 $ 236,347 Adjusted Efficiency Ratio (non-GAAP) 63.38% 62.89% 64.75% 60.52% 57.72% Fully taxable equivalent adjustment using an effective tax rate of 26.135% 32

Non-GAAP Reconciliations 3Q 2Q 3Q 2024 2025 2025 $ in thousands Calculation of Adjusted Salaries and Employee Benefits Salaries and employee benefits (GAAP) $ 69,167 $ 73,862 $ 76,249 Less: Early retirement program (1) 1,594 305 Less: Other 1 (1) 1 Total Adjusted Salaries and Employee Benefits (non-GAAP) $ 69,167 $ 72,269 $ 75,943 Calculation of Adjusted Occupancy Expense, Net Occupancy expense, net (GAAP) $ 12,216 $ 11,844 $ 12,106 Less: Branch right sizing expense 224 396 432 Total Adjusted Occupancy Expense (non-GAAP) $ 11,992 $ 11,448 $ 11,674 Calculation of Adjusted Furniture and Equipment Expense Furniture and Equipment Expense (GAAP) $ 5,612 $ 5,474 $ 5,275 Less: Branch right sizing expense 1 23 15 Total Adjusted Furniture and Equipment Expense (non-GAAP) $ 5,611 $ 5,451 $ 5,260 Calculation of Adjusted Other Noninterest Expense Other noninterest expense (GAAP) $ 44,540 $ 42,276 $ 43,027 Less: Branch right sizing expense (13) (255) 1,556 Less: Termination of vendor and software services 184 - - Total Adjusted Other Noninterest Expense (non-GAAP) $ 44,369 $ 42,531 $ 41,471 Calculation of Adjusted Provision for Income Taxes Provision for income taxes (GAAP) $ 761 $ 8,871 $ (160,732) Less: Tax effect of certain items (non-GAAP) (reconciliation shown on page 29) (7,524) (459) (176,649) Adjusted provision for income taxes (non-GAAP) $ 8,285 $ 9,330 $ 15,917 33

Non-GAAP Reconciliations 3Q 2Q 3Q 2024 2025 2025 $ in thousands Calculation of Uninsured, Non-Collateralized Deposit Coverage Ratio Uninsured deposits at Simmons Bank $ 8,355,496 $ 8,407,847 $ 9,565,766 Less: Collateralized deposits (excluding portion that is FDIC insured) 2,710,167 2,691,215 2,169,362 Less: Intercompany eliminations ______ 986,626 _____1,121,932 _____2,937,147 Total uninsured, non-collateralized deposits (non-GAAP) $ 4,658,703 $ 4,594,700 $ 4,459,257 FHLB borrowing availability $ 4,955,000 $ 5,133,000 $ 6,134,000 Unpledged securities 4,110,000 3,697,000 1,575,000 Fed funds lines and Fed discount window 2,109,000 1,894,000 1,824,000 Additional liquidity sources $ 11,174,000 $ 10,724,000 $ 9,533,000 Uninsured, non-collateralized deposit coverage ratio (non-GAAP) 2.4x 2.3x 2.1x Calculation of Net Charge-Off Ratio, Excluding Run-Off Portfolio Net charge-offs $ 9,314 $ 10,576 $ 10,711 Less: Net charge-offs from run-off portfolio ______ 3,500 ______ 1,100 ______ 500 Net charge-offs excluding run-off portfolio (non-GAAP) $ 5,814 $ 9,476 $ 10,211 Average total loans $ 17,208,162 $ 17,046,802 $ 16,976,231 Net charge-offs as a percentage of average total loans (annualized) (NCO ratio) 0.22% 0.25% 0.25% NCO ratio excluding NCOs associated with run-off portfolios (annualized) (non- GAAP) 0.13% 0.22% 0.24% 34

Non-GAAP Reconciliations 1Q 2Q 3Q 2025 2025 2025 $ in thousands Calculation of NPL ratio, excluding Two Specific Credit Relationships Nonperforming loans $ 152,391 $ 157,162 $ 153,939 Less: Two Specific Credit Relationships 49,761 49,572 49,267 Nonperforming Loans, excluding Two Specific Credit Relationships (non-GAAP) $ 102,630 $ 107,590 $ 104,672 Total loans $ 17,094,078 $ 17,111,096 $ 17,188,817 Less: Two Specific Credit Relationships 49,761 49,572 49,267 Total Loans, excluding Two Specific Credit Relationships (non-GAAP) $ 17,044,317 $ 17,061,524 $ 17,139,550 Nonperforming loans ratio (NPL Ratio) 0.89% 0.92% 0.90% NPL ratio, excluding Two Specific Credit Relationships (non-GAAP) 0.60% 0.63% 0.61% Calculation of NPA to Total Assets, excluding Two Specific Credit Relationships Nonperforming assets $ 162,345 $ 166,715 $ 160,717 Less: Two Specific Credit Relationships 49,761 49,572 49,267 Nonperforming Assets, excluding Two Specific Credit Relationships (non-GAAP) $ 112,584 $ 117,143 $ 111,450 Total assets $ 26,792,991 $ 26,693,620 $ 24,208,162 Less: Two Specific Credit Relationships 49,761 49,572 49,267 Total Assets, excluding Two Specific Credit Relationships (non-GAAP) $ 26,743,230 $ 26,644,048 $ 24,158,895 Nonperforming assets to total assets 0.61% 0.62% 0.66% Nonperforming assets to total assets, excluding Two Specific Credit Relationships (non-GAAP) 0.42% 0.44% 0.46% 35

Non-GAAP Reconciliations 2Q 3Q 2Q 3Q 2025 2025 2025 2025 $ in thousands $ in thousands Calculation of Tangible Common Equity (TCE) Calculation of Adjusted ROAA Total common stockholders’ equity $ 3,549,210 $ 3,353,963 Net income $ 54,773 $ (562,792) Less: Intangible assets 1,411,416 1,408,319 Adjusted earnings (non-GAAP) (reconciliation shown on page 29) $ 56,071 $ 64,930 Total tangible common stockholders’ equity (non-GAAP) $ 2,137,794 $ 1,945,644 Average assets $ 26,645,131 $ 24,914,922 Total assets $ 26,693,620 $ 24,208,162 Return on average assets (ROAA) 0.82% (8.96)% Less: Intangible assets 1,411,416 1,408,319 Adjusted ROAA (non-GAAP) 0.84% 1.03% Total tangible assets $ 25,282,204 $ 22,799,843 Calculation of Adjusted ROTCE Common equity to total assets 13.30% 13.85% Net income $ 54,773 $ (562,792) Tangible common equity to tangible common assets (non-GAAP) 8.46% 8.53% Plus: Amortization of intangible assets, net of taxes 2,289 2,287 Total tangible net income (non-GAAP) $ 57,062 $ (560,505) Adjusted earnings (non-GAAP) (reconciliation shown on page 29) $ 56,071 $ 64,930 Plus: Amortization of intangible assets, net of taxes 2,289 2,287 Total adjusted tangible net income (non-GAAP) $ 58,360 $ 67,217 Average common stockholders’ equity $ 3,546,163 $ 3,368,308 Less: Average intangible assets 1,413,231 1,410,148 Average tangible common stockholders’ equity (non-GAAP) $ 2,132,932 $ 1,958,160 Return on average common equity (ROCE) 6.20% (66.29)% Return on average tangible common equity (ROTCE) (non-GAAP) 10.73% (113.56)% Adjusted return on average common equity (non-GAAP) 6.34% 7.65% Adjusted return on tangible common equity (non-GAAP) 10.97% 13.62% 36

Non-GAAP Reconciliations 2Q 2Q 2025 2025 $ in thousands $ in thousands Calculation of Tier 1 Leverage Ratio Calculation of Total Risk-Based Capital Ratio Stockholders’ equity $ 3,549,210 Tier 1 capital $ 2,551,006 Less: Disallowed intangible assets, net of deferred tax 1,379,104 Plus: Subordinated notes and debentures 366,369 Less: Unrealized loss (gain) on AFS securities 380,900 Less: Subordinated debt phase out (198,000) Tier 1 capital $ 2,551,006 Plus: Qualifying allowance for credit losses and reserve for unfunded commitments 258,079 Total risk-based capital $ 2,977,454 Tier 1 capital $ 2,551,006 Less: Market value adjustment on HTM securities transferred to AFS, net of tax 501,063 Total risk-based capital $ 2,977,454 Adjusted Tier 1 capital $ 2,049,943 Less: Loss on securities sale and repositioning 606,729 Adjusted total risk-based capital $ 2,370,725 Average assets for leverage ratio $ 25,606,135 Less: Market value adjustment on HTM securities transferred to AFS, net of tax 501,063 Risk weighted assets $ 20,646,324 Adjusted average assets for leverage ratio $ 25,105,072 Less: Securities sale and repositioning (assuming 32.9% risk weighting) 943,205 Adjusted risk weighted assets $ 19,703,119 Tier 1 Leverage Ratio 9.96% Adjusted Tier 1 Leverage Ratio (Economic Capital) (non-GAAP) 8.17% Total Risk-Based Capital Ratio 14.42% Adjusted Total Risk-Based Capital Ratio (Economic Capital) (non-GAAP) 12.03% 1 Calculation of CET 1 Capital Ratio Tier 1 capital $ 2,551,006 Less: Loss on securities sale and repositioning 606,729 Adjusted Tier 1 capital $ 1,944,277 Risk weighted assets $ 20,646,324 Less: Securities sale and repositioning (assuming 32.9% risk weighting) 943,205 Adjusted risk weighted assets $ 19,703,119 CET 1 Capital Ratio 12.36% Adjusted CET 1 Capital Ratio Ratio (Economic Capital) (non-GAAP) 9.87% 1 At June 30, 2025, the CET 1 Capital Ratio and the Tier 1 Risk-Based Capital Ratio were the same for the Company 37

Non-GAAP Reconciliations September September 2025 2025 $ in thousands $ in thousands Calculation of Adjusted ROAA Calculation of Pre-Provision Net Revenue (PPNR) Net income $ 21,147 Net interest income $ 63,171 Plus: Branch right sizing costs 1,788 Plus: Noninterest income 15,734 Plus : Loss on early extinguishment of debt 570 Less: Noninterest expense 49,802 Less: Tax effect (616) Pre-Provision Net Revenue (PPNR) (non-GAAP) $ 29,103 Adjusted earnings (non-GAAP) $ 22,889 Calculation of Adjusted Pre-Provision Net Revenue Pre-Provision Net Revenue (PPNR) (non-GAAP) $ 29,103 Average assets $ 24,162,450 Plus: Branch right sizing costs, net 1,788 Return on average assets (ROAA) 1.06% Plus: Loss on early extinguishment of debt 570 Adjusted ROAA (non-GAAP) 1.15% Adjusted Pre-Provision Net Revenue (non-GAAP) $ 31,461 Calculation of Adjusted ROTCE Adjusted Pre-Provision Net Revenue (Non-GAAP) quarterized $ 96,480 Net income $ 21,147 Plus: Amortization of intangible assets, net of taxes 762 Total tangible net income (non-GAAP) $ 21,909 Adjusted earnings (non-GAAP) (reconciliation shown above) $ 22,889 Plus: Amortization of intangible assets, net of taxes 762 Total adjusted tangible net income (non-GAAP) $ 23,651 Average common stockholders’ equity $ 3,343,526 Less: Average intangible assets 1,409,145 Average tangible common stockholders’ equity (non-GAAP) $ 1,934,381 Return on average common equity (ROCE) 7.70% Return on average tangible common equity (ROTCE) (non-GAAP) 13.78% Adjusted return on average common equity (non-GAAP) 8.33% Adjusted return on tangible common equity (non-GAAP) 14.88% 38

Nasdaq SFNC rd 3 Quarter 2025 Earnings Presentation October 16, 2025