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Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
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SCHEDULE 13D/A 0001530950-25-000082 0001052058 XXXXXXXX LIVE 3 Common Stock, $0.01 par value 10/15/2025 false 0001530950 737446104 Post Holdings, Inc. 2503 S. Hanley Rd St. Louis MO 63144 William P. Stiritz 618-398-7781 790 Briar Hill Road Belleville IL 62223 0001052058 N William P. Stiritz PF OO N X1 4498836.00 384132.00 4498836.00 384132.00 4882968.00 N 9.3 IN The percent ownership information included on line 13 above in this Amendment No. 3 to Schedule 13D is based on 52,604,677 shares of Common Stock, par value $0.01 per share, of Post Holdings, Inc., a Missouri corporation (the "Issuer"), issued and outstanding as of October 15, 2025, according to information provided by the Issuer. Common Stock, $0.01 par value Post Holdings, Inc. 2503 S. Hanley Rd St. Louis MO 63144 EXPLANATORY NOTE - This Amendment No. 3 to Schedule 13D relates to the Schedule 13D filed by William P. Stiritz (the "Reporting Person") with the Securities and Exchange Commission (the "SEC") on December 1, 2016 (the "Initial Schedule 13D"), as amended by Amendment No. 1 to Schedule 13D filed with the SEC on February 22, 2021 ("Amendment No. 1") and Amendment No. 2 to Schedule 13D filed with the SEC on February 14, 2025 ("Amendment No. 2" and the Initial Schedule 13D as amended by Amendment No. 1 and Amendment No. 2, the "Schedule 13D"), and amends the Schedule 13D as specifically set forth herein. Items 5(a)-(e) of the Schedule 13D are hereby amended and restated as follows: As of the date hereof, the Reporting Person beneficially owns, in the aggregate, 4,882,968 shares of Common Stock of the Issuer (the "Common Stock"), representing approximately 9.28% of the Issuer's outstanding shares of Common Stock. The Reporting Person beneficially owns shares of Common Stock of the Issuer directly (4,329,467 shares) and through The Wildwood Trust, of which the Reporting Person is Trustee (169,369 shares), and through his spouse, Susan Stiritz (384,132 shares). The number of shares as to which there is sole power to vote or to direct the vote is 4,498,836. The number of shares as to which there is the shared power to vote or to direct the vote is 384,132. The number of shares as to which there is sole power to dispose or to direct the disposition is 4,498,836. The number of shares as to which there is shared power to dispose or to direct the disposition is 384,132. The Reporting Person shares voting and disposition rights with his spouse with respect to 384,132 shares. Susan Stiritz's address is 790 Briar Hill Road, Belleville, Illinois 62223. Mrs. Stiritz is retired and is a professor of practice emeritus at Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130. During the last five years, Mrs. Stiritz has not been convicted in a criminal proceeding. During the last five years, Mrs. Stiritz has not been a party to a civil proceeding of a judicial or administrative body of competent jurisdiction which resulted in her being subject to a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws. Mrs. Stiritz is a citizen of the United States. Other than the following, the Reporting Person has effected no transactions in the Common Stock of the Issuer within the past sixty days: On August 19, 2025, the Reporting Person purchased 36,000 shares of Common Stock of the Issuer in the open market for $109.53 per share. Except for the Reporting Person's spouse, no person other than the Reporting Person has the right to receive dividends on, and any proceeds from the disposition of, any shares of Common Stock reported as owned by him in this Item 5 above. Not applicable. William P. Stiritz /s/ William P. Stiritz William P. Stiritz 10/15/2025