Please wait

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0104 Estimated average burden hours per response: 0.5

1. Name and Address of Reporting Person* MILLENNIUM MANAGEMENT LLC (Last) (First) (Middle) 399 PARK AVENUE (Street) NEW YORK NY 10022 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 03/26/2026	3. Issuer Name and Ticker or Trading Symbol Sensei Biotherapeutics, Inc. [ SNSE ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. If Amendment, Date of Original Filed (Month/Day/Year)
			6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	127,095	I	See Footnote(1)(2)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

1. Name and Address of Reporting Person* MILLENNIUM MANAGEMENT LLC (Last) (First) (Middle) 399 PARK AVENUE (Street) NEW YORK NY 10022 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ICS OPPORTUNITIES II LLC (Last) (First) (Middle) C/O MILLENNIUM MANAGEMENT LLC 399 PARK AVENUE (Street) NEW YORK NY 10022 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* MILLENNIUM GROUP MANAGEMENT LLC (Last) (First) (Middle) 399 PARK AVENUE (Street) NEW YORK NY 10022 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ENGLANDER ISRAEL A (Last) (First) (Middle) C/O MILLENNIUM MANAGEMENT LLC 399 PARK AVENUE (Street) NEW YORK NY 10022 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. The shares of Sensei Biotherapeutics, Inc. (the "Company") common stock ("Common Stock"), par value $0.0001 per share, disclosed herein were held by ICS Opportunities II LLC or other trading entities, in each case subject to voting control and investment discretion by Millennium Management LLC, Millennium Group Management LLC (the managing member of Millennium Management LLC) and Israel A. Englander (the sole voting trustee of the managing member of Millennium Group Management LLC).

2. ICS Opportunities II LLC held 126,828 shares of the Company's Common Stock. Other trading entities subject to voting control and investment discretion by Millennium Management LLC held an aggregate of 267 shares of the Company's Common Stock. Each reporting person disclaims beneficial ownership of the shares of the Company's Common Stock disclosed herein except to the extent of such reporting person's pecuniary interest therein, if any.

	MILLENNIUM MANAGEMENT LLC: By: /s/ Gil Raviv, Global General Counsel	05/14/2026
	ICS OPPORTUNITIES II LLC, By: Millennium Management LLC, its Investment Manager: By: /s/ Gil Raviv, Global General Counsel	05/14/2026
	MILLENNIUM GROUP MANAGEMENT LLC: By: /s/ Gil Raviv, Global General Counsel	05/14/2026
	/s/ Israel A. Englander	05/14/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.