Citadel-affiliated investment entities filed an amended Schedule 13G reporting beneficial ownership in Lexeo Therapeutics, Inc. common stock. The filing states that Kenneth Griffin may be deemed to beneficially own 5,498,219 Shares, representing 7.4% of Lexeo’s outstanding common stock.
Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC may each be deemed to beneficially own 5,405,269 Shares, or 7.2% of the class, while certain Citadel Securities entities report smaller positions of 6,600 and 92,950 Shares. The percentages are based on 74,704,629 Shares outstanding, including 1,717,302 Shares issuable upon warrant conversion. The reporting persons certify the securities are not held to change or influence control of Lexeo.
Positive
None.
Negative
None.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 3)
Lexeo Therapeutics, Inc.
(Name of Issuer)
Common Stock ($0.0001 par value) (the "Shares")
(Title of Class of Securities)
52886X107
(CUSIP Number)
12/31/2025
(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)
SCHEDULE 13G
CUSIP No.
52886X107
1
Names of Reporting Persons
Citadel Advisors 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
5,405,269.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,405,269.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,405,269.00
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)
7.2 %
12
Type of Reporting Person (See Instructions)
IA, HC, OO
Comment for Type of Reporting Person: The percentages reported in this Schedule 13G are based upon 74,704,629 Shares outstanding comprised of (i) 72,987,327 Shares outstanding as of November 3, 2025 (according to the issuer's registration statement on From 10-Q as filed with the Securities and Exchange Commission on November 5, 2025), and (ii) 1,717,302 Shares issuable upon conversion of certain warrants held by affiliates of the reporting persons.
SCHEDULE 13G
CUSIP No.
52886X107
1
Names of Reporting Persons
Citadel Advisors Holdings LP
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
5,405,269.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,405,269.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,405,269.00
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)
7.2 %
12
Type of Reporting Person (See Instructions)
HC, PN
SCHEDULE 13G
CUSIP No.
52886X107
1
Names of Reporting Persons
Citadel GP 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
5,405,269.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,405,269.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,405,269.00
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)
7.2 %
12
Type of Reporting Person (See Instructions)
HC, OO
SCHEDULE 13G
CUSIP No.
52886X107
1
Names of Reporting Persons
Citadel Securities 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
6,600.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
6,600.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
6,600.00
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)
0.0 %
12
Type of Reporting Person (See Instructions)
BD, OO
SCHEDULE 13G
CUSIP No.
52886X107
1
Names of Reporting Persons
Citadel Securities Group LP
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
92,950.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
92,950.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
92,950.00
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)
0.1 %
12
Type of Reporting Person (See Instructions)
HC, PN
SCHEDULE 13G
CUSIP No.
52886X107
1
Names of Reporting Persons
Citadel Securities GP 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
92,950.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
92,950.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
92,950.00
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)
0.1 %
12
Type of Reporting Person (See Instructions)
HC, OO
SCHEDULE 13G
CUSIP No.
52886X107
1
Names of Reporting Persons
Kenneth Griffin
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
5,498,219.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
5,498,219.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
5,498,219.00
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)
7.4 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Lexeo Therapeutics, Inc.
(b)
Address of issuer's principal executive offices:
345 Park Avenue South, Floor 6, New York, NY, 10010
Item 2.
(a)
Name of person filing:
This Schedule 13G is being jointly filed by Citadel Advisors LLC ("Citadel Advisors"), Citadel Advisors Holdings LP ("CAH"), Citadel GP LLC ("CGP"), Citadel Securities LLC ("Citadel Securities"), Citadel Securities Group LP ("CALC4"), Citadel Securities GP LLC ("CSGP") and Mr. Kenneth Griffin (collectively with Citadel Advisors, CAH, CGP, Citadel Securities, CALC4 and CSGP, the "Reporting Persons") with respect to the Shares of the above-named issuer owned by Citadel Multi-Strategy Equities Master Fund Ltd., a Cayman Islands company ("CM"), Citadel CEMF Investments Ltd., a Cayman Islands limited company ("CCIL"), Citadel Securities, and CRBU Holdings LLC, a Delaware limited liability company ("CRBH"). Such owned Shares may include other instruments exercisable for or convertible into Shares.
Citadel Advisors is the portfolio manager for CM and CCIL. CAH is the sole member of Citadel Advisors. CGP is the general partner of CAH. CALC4 is the non-member manager of Citadel Securities and CRBH. CSGP is the general partner of CALC4. Mr. Griffin is the President and Chief Executive Officer of CGP, and owns a controlling interest in CGP and CSGP.
The filing of this statement shall not be construed as an admission that any of the Reporting Persons is the beneficial owner of any securities covered by the statement other than the securities actually owned by such person (if any).
(b)
Address or principal business office or, if none, residence:
The address of each of the Reporting Persons is 830 Brickell Plaza, Miami, Florida 33131.
(c)
Citizenship:
Each of Citadel Advisors, CGP, Citadel Securities and CSGP is organized as a limited liability company under the laws of the State of Delaware. Each of CALC4 and CAH is organized as a limited partnership under the laws of the State of Delaware. Mr. Griffin is a U.S. citizen.
(d)
Title of class of securities:
Common Stock ($0.0001 par value) (the "Shares")
(e)
CUSIP No.:
52886X107
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:
1. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC may be deemed to beneficially own 5,405,269 Shares.
2. Citadel Securities LLC may be deemed to beneficially own 6,600 Shares.
3. Each of Citadel Securities Group LP and Citadel Securities GP LLC may be deemed to beneficially own 92,950 Shares.
4. Mr. Griffin may be deemed to beneficially own 5,498,219 Shares.
(b)
Percent of class:
1. The number of Shares that each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC may be deemed to beneficially own constitutes 7.2% of the Shares outstanding.
2. The number of Shares that Citadel Securities LLC may be deemed to beneficially own constitutes 0.0% of the Shares outstanding.
3. The number of Shares that each of Citadel Securities Group LP and Citadel Securities GP LLC may be deemed to beneficially own constitutes 0.1% of the Shares outstanding.
4. The number of Shares that Mr. Griffin may be deemed to beneficially own constitutes 7.4% of the Shares outstanding.
(c)
Number of shares as to which the person has:
(i) Sole power to vote or to direct the vote:
1. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC: 0
2. Citadel Securities LLC: 0
3. Each of Citadel Securities Group LP and Citadel Securities GP LLC: 0
4. Mr. Griffin: 0
(ii) Shared power to vote or to direct the vote:
1. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC: 5,405,269
2. Citadel Securities LLC: 6,600
3. Each of Citadel Securities Group LP and Citadel Securities GP LLC: 92,950
4. Mr. Griffin: 5,498,219
(iii) Sole power to dispose or to direct the disposition of:
1. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC: 0
2. Citadel Securities LLC: 0
3. Each of Citadel Securities Group LP and Citadel Securities GP LLC: 0
4. Mr. Griffin: 0
(iv) Shared power to dispose or to direct the disposition of:
1. Each of Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC: 5,405,269
2. Citadel Securities LLC: 6,600
3. Each of Citadel Securities Group LP and Citadel Securities GP LLC: 92,950
4. Mr. Griffin: 5,498,219
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.
Not Applicable
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.
Citadel Advisors LLC
Signature:
/s/ Seth Levy
Name/Title:
Seth Levy, Authorized Signatory
Date:
02/17/2026
Citadel Advisors Holdings LP
Signature:
/s/ Seth Levy
Name/Title:
Seth Levy, Authorized Signatory
Date:
02/17/2026
Citadel GP LLC
Signature:
/s/ Seth Levy
Name/Title:
Seth Levy, Authorized Signatory
Date:
02/17/2026
Citadel Securities LLC
Signature:
/s/ Seth Levy
Name/Title:
Seth Levy, Authorized Signatory
Date:
02/17/2026
Citadel Securities Group LP
Signature:
/s/ Seth Levy
Name/Title:
Seth Levy, Authorized Signatory
Date:
02/17/2026
Citadel Securities GP LLC
Signature:
/s/ Seth Levy
Name/Title:
Seth Levy, Authorized Signatory
Date:
02/17/2026
Kenneth Griffin
Signature:
/s/ Seth Levy
Name/Title:
Seth Levy, attorney-in-fact*
Date:
02/17/2026
Comments accompanying signature: * Seth Levy is signing on behalf of Kenneth Griffin as attorney-in-fact pursuant to a power of attorney previously filed with the Securities and Exchange Commission, and hereby incorporated by reference herein. The power of attorney was filed as an attachment to a filing by Citadel Advisors LLC on Schedule 13G for Allakos Inc. on October 13, 2023.
How much of Lexeo Therapeutics (LXEO) does Kenneth Griffin report owning?
Kenneth Griffin may be deemed to beneficially own 5,498,219 Shares of Lexeo Therapeutics common stock, according to the amended Schedule 13G. This represents 7.4% of the company’s outstanding common stock based on the share count disclosed.
What Lexeo Therapeutics stake do Citadel Advisors entities report in this Schedule 13G/A?
Citadel Advisors LLC, Citadel Advisors Holdings LP and Citadel GP LLC may each be deemed to beneficially own 5,405,269 Shares of Lexeo Therapeutics. The filing states this position represents 7.2% of Lexeo’s outstanding common stock, based on the share total described.
What share count is used to calculate the ownership percentages for LXEO?
The reported ownership percentages are based on 74,704,629 Shares of Lexeo Therapeutics common stock outstanding. This figure includes 72,987,327 Shares outstanding as of November 3, 2025, plus 1,717,302 Shares issuable upon conversion of certain warrants.
Are the Citadel-related holdings in Lexeo reported as passive investments?
The reporting persons certify the Lexeo securities were not acquired and are not held for the purpose of changing or influencing control of the issuer. They also state the holdings are not part of any transaction having that control-related purpose or effect, subject to the nomination exception cited.
Which entities are identified as reporting persons in the Lexeo (LXEO) Schedule 13G/A?
The filing lists Citadel Advisors LLC, Citadel Advisors Holdings LP, Citadel GP LLC, Citadel Securities LLC, Citadel Securities Group LP, Citadel Securities GP LLC, and Kenneth Griffin as reporting persons with respect to Lexeo Therapeutics common stock.
What voting and dispositive power do Citadel entities report over Lexeo shares?
The filing shows the Citadel-related entities and Kenneth Griffin have 0 Shares with sole voting or dispositive power. They report shared voting and shared dispositive power over the Lexeo positions, including 5,405,269 Shares for certain Citadel entities and 5,498,219 Shares for Kenneth Griffin.
