Sensei Biotherapeutics reported a joint Schedule 13G from ICS Opportunities II LLC, Millennium Management LLC, Millennium Group Management LLC and Israel A. Englander disclosing shared beneficial ownership stakes in Common Stock. The reporting persons stated they beneficially owned 84,541 shares (6.7%) as of February 24, 2026, increased to 127,095 shares (10.1%) on March 26, 2026, and were reported as holding 128,761 shares (9.6%) as of May 14, 2026. The filing ties calculations to 1,261,290 shares outstanding (as of November 10, 2025) and 1,341,140 shares outstanding (as of April 13, 2026) cited from company filings.
Positive
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Negative
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Insights
Joint filing discloses passive accumulation to near 10% class ownership.
The joint Schedule 13G lists combined beneficial ownership of 128,761 shares representing 9.6% as of May 14, 2026. The filing attributes shared voting and dispositive power across affiliated entities, with specific shared holdings shown per cover pages.
Key dependencies include the company’s reported share counts of 1,261,290 and 1,341,140 used in percentage calculations. Future disclosures may clarify whether positions change or convert to a Schedule 13D if active intentions shift.
Ownership is held indirectly through affiliated investment entities and disclosed via a joint filing agreement.
The filing explains that shares are held by entities under the investment control of Millennium Management LLC and related managers; signatures and an Exhibit I joint filing agreement are included. The filing notes shared voting/dispositive power amounts such as 127,917 and 128,761 in the cover-page rows.
Cash‑flow treatment and trading intent are not stated in the excerpt; the mechanics of control and exact entity-level holdings are in the attached exhibits and cover pages.
Key Figures
Shares owned (May 14, 2026):128,761 sharesPercent of class (May 14, 2026):9.6%Shares owned (Feb 24, 2026):84,541 shares+3 more
6 metrics
Shares owned (May 14, 2026)128,761 sharesReported combined beneficial ownership as of May 14, 2026
Percent of class (May 14, 2026)9.6%Percentage based on company share count as of April 13, 2026
Shares owned (Feb 24, 2026)84,541 sharesCombined beneficial ownership as of February 24, 2026
Shares owned (Mar 26, 2026)127,095 sharesCombined beneficial ownership after surpassing 10% on March 26, 2026
Outstanding shares (Nov 10, 2025)1,261,290 sharesShares outstanding cited from company's 10-Q filed Nov 14, 2025
Outstanding shares (Apr 13, 2026)1,341,140 sharesShares outstanding cited from company proxy filed Apr 27, 2026
"Item 1. | (a) | Name of issuer: Sensei Biotherapeutics, Inc."
A Schedule 13G is a formal document that investors file with the government when they acquire a large ownership stake in a company, usually for investment purposes rather than control. It helps keep the public informed about who owns significant parts of a company's shares, which can influence how the company is managed and how investors make decisions. Filing this schedule is important for transparency and understanding the ownership landscape of publicly traded companies.
Beneficially ownedfinancial
"As of the close of business on February 24, 2026, the reporting persons beneficially owned an aggregate of 84,541 shares"
Beneficially owned describes securities or assets where a person has the economic rights and control—such as the right to receive dividends and to direct voting—even if legal title is held in another name. Think of it like having the keys and using a car that’s registered to someone else: you get the benefits and make decisions. Investors care because beneficial ownership reveals who truly controls value and voting power, affecting corporate decisions and takeover dynamics.
Shared dispositive powergovernance
"Shared Dispositive Power 128,761.00"
Joint Filing Agreementregulatory
"Exhibit I: Joint Filing Agreement, dated as of May 14, 2026"
The joint filing reports combined beneficial ownership of 128,761 shares (9.6%) as of May 14, 2026. Earlier reported positions were 84,541 shares (6.7%) as of February 24, 2026 and 127,095 shares (10.1%) on March 26, 2026.
Which entities filed the Schedule 13G for SNSE?
The Schedule 13G is filed jointly by ICS Opportunities II LLC, Millennium Management LLC, Millennium Group Management LLC and Israel A. Englander, with a Joint Filing Agreement attached as Exhibit I dated May 14, 2026.
What share counts were used to calculate percentages in the SNSE filing?
Percentages use 1,261,290 shares outstanding (as of November 10, 2025) and 1,341,140 shares outstanding (as of April 13, 2026), cited from the company’s 10-Q and proxy statement, respectively.
Does the filing state who has voting or dispositive power for the SNSE shares?
The filing discloses shared voting and shared dispositive power for the reported share amounts; specific per-entity rows show shared voting/dispositive figures such as 127,917 and 128,761 in the cover-page entries.
Is trading intent or cash-flow treatment disclosed in the SNSE Schedule 13G?
The excerpt does not state trading intent or cash-flow treatment; it describes beneficial ownership and that holdings are held by entities subject to investment discretion by Millennium-related managers.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
Sensei Biotherapeutics, Inc.
(Name of Issuer)
Common Stock, par value $0.0001 per share
(Title of Class of Securities)
81728A207
(CUSIP Number)
02/24/2026
(Date of Event Which Requires Filing of this Statement)
Check the appropriate box to designate the rule pursuant to which this Schedule is filed:
Rule 13d-1(b)
Rule 13d-1(c)
Rule 13d-1(d)
schemaVersion:
SCHEDULE 13G
CUSIP Number(s):
81728A207
1
Names of Reporting Persons
ICS Opportunities II LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
CAYMAN ISLANDS
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
127,917.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
127,917.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
127,917.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
9.5 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
81728A207
1
Names of Reporting Persons
Millennium Management LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
128,761.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
128,761.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
128,761.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
9.6 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
81728A207
1
Names of Reporting Persons
Millennium Group Management LLC
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
128,761.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
128,761.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
128,761.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
9.6 %
12
Type of Reporting Person (See Instructions)
OO
SCHEDULE 13G
CUSIP Number(s):
81728A207
1
Names of Reporting Persons
Israel A. Englander
2
Check the appropriate box if a member of a Group (see instructions)
(a)
(b)
3
Sec Use Only
4
Citizenship or Place of Organization
UNITED STATES
Number of Shares Beneficially Owned by Each Reporting Person With:
5
Sole Voting Power
0.00
6
Shared Voting Power
128,761.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
128,761.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
128,761.00
10
Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)
11
Percent of class represented by amount in row (9)
9.6 %
12
Type of Reporting Person (See Instructions)
IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Sensei Biotherapeutics, Inc.
(b)
Address of issuer's principal executive offices:
1405 Research Boulevard, Suite 125, Rockville, Maryland 20850
Item 2.
(a)
Name of person filing:
ICS Opportunities II LLC
Millennium Management LLC
Millennium Group Management LLC
Israel A. Englander
(b)
Address or principal business office or, if none, residence:
ICS Opportunities II LLC
c/o Millennium Management LLC
399 Park Avenue
New York, New York 10022
Millennium Management LLC
399 Park Avenue
New York, New York 10022
Millennium Group Management LLC
399 Park Avenue
New York, New York 10022
Israel A. Englander
c/o Millennium Management LLC
399 Park Avenue
New York, New York 10022
(c)
Citizenship:
ICS Opportunities II LLC - Cayman Islands
Millennium Management LLC - Delaware
Millennium Group Management LLC - Delaware
Israel A. Englander - United States
(d)
Title of class of securities:
Common Stock, par value $0.0001 per share
(e)
CUSIP Number(s):
81728A207
Item 3.
If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)
Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)
Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)
Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)
Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)
An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)
An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)
A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)
A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)
A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)
A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J),
please specify the type of institution:
(k)
Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.
Ownership
(a)
Amount beneficially owned:
See response to Item 9 on each cover page.
As of the close of business on February 24, 2026, the reporting persons beneficially owned an aggregate of 84,541 shares of common stock, par value $0.0001 per share ("Common Stock") or 6.7% of the Common Stock outstanding. After acquiring beneficial ownership of more than 10% of the outstanding Common Stock on March 26, 2026, the reporting persons beneficially owned 127,095 shares of Common Stock or 10.1% of the Common Stock outstanding. As of the close of business on May 14, 2026, the reporting persons beneficially owned an aggregate of 128,761 shares of Common Stock or 9.6% of the Common Stock outstanding. The information reported on each cover page is as of the close of business on May 14, 2026.
Calculations herein prior to May 14, 2026 are based on 1,261,290 shares of Common Stock outstanding as November 10, 2025, as reported by Sensei Biotherapeutics, Inc. (the "Company") on its 10-Q filed on November 14, 2025. Calculations as of May 14, 2026 are based on 1,341,140 shares of Common Stock outstanding as of April 13, 2026, as reported by the Company in the proxy statement filed on April 27, 2026.
(b)
Percent of class:
See response to Item 11 on each cover page.
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
See response to Item 5 on each cover page.
(ii) Shared power to vote or to direct the vote:
See response to Item 6 on each cover page.
(iii) Sole power to dispose or to direct the disposition of:
See response to Item 7 on each cover page.
(iv) Shared power to dispose or to direct the disposition of:
See response to Item 8 on each cover page.
The securities disclosed herein as potentially beneficially owned by Millennium Management LLC, Millennium Group Management LLC and Mr. Englander are held by entities subject to voting control and investment discretion by Millennium Management LLC and/or other investment managers that may be controlled by Millennium Group Management LLC (the managing member of Millennium Management LLC) and Mr. Englander (the sole voting trustee of the managing member of Millennium Group Management LLC). The foregoing should not be construed in and of itself as an admission by Millennium Management LLC, Millennium Group Management LLC or Mr. Englander as to beneficial ownership of the securities held by such entities.
Item 5.
Ownership of 5 Percent or Less of a Class.
Not Applicable
Item 6.
Ownership of more than 5 Percent on Behalf of Another Person.
Not Applicable
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
Not Applicable
Item 8.
Identification and Classification of Members of the Group.
If a group has filed this schedule pursuant to §240.13d-1(b)(1)(ii)(K), so indicate under Item 3(k) and attach an exhibit stating the identity and Item 3 classification of each member of the group. If a group has filed this schedule pursuant to §240.13d-1(c) or §240.13d-1(d), attach an exhibit stating the identity of each member of the group.
See Exhibit I
Item 9.
Notice of Dissolution of Group.
Not Applicable
Item 10.
Certifications:
By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11.
SIGNATURE
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.
ICS Opportunities II LLC
Signature:
/s/ Gil Raviv
Name/Title:
Gil Raviv, Global General Counsel
Date:
05/14/2026
Millennium Management LLC
Signature:
/s/ Gil Raviv
Name/Title:
Gil Raviv, Global General Counsel
Date:
05/14/2026
Millennium Group Management LLC
Signature:
/s/ Gil Raviv
Name/Title:
Gil Raviv, Global General Counsel
Date:
05/14/2026
Israel A. Englander
Signature:
/s/ Israel A. Englander
Name/Title:
Israel A. Englander
Date:
05/14/2026
Comments accompanying signature: ** ICS OPPORTUNITIES II LLC
By: Millennium Management LLC, its Investment Manager
Exhibit Information
Exhibit I: Joint Filing Agreement, dated as of May 14, 2026, by and among ICS Opportunities II LLC, Millennium Management LLC, Millennium Group Management LLC and Israel A. Englander.
