Sutro Biopharma, Inc. investors received an update on institutional ownership as Suvretta Capital Management, Averill Master Fund, and Aaron Cowen reported no beneficial ownership of the company’s common stock. Each reporting person lists 0 shares beneficially owned, representing 0% of the class, with no sole or shared voting or dispositive power.
The filing notes that all securities previously reported are directly owned by advisory clients of Suvretta Capital Management, and that none of those clients may be deemed to beneficially own more than 5% of Sutro’s common stock. The reporting persons also certify that the securities are not held to change or influence control of the company.
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Insights
Key institutional filer now reports 0% beneficial ownership in Sutro.
Suvretta Capital Management, Averill Master Fund, and Aaron Cowen each report beneficial ownership of 0 shares of Sutro Biopharma common stock, or 0% of the class, with no voting or dispositive power. This represents a move to below the 5% ownership disclosure threshold.
The filing states that all securities referenced are directly owned by advisory clients of Suvretta Capital Management and that none of these clients may be deemed to own more than 5% of the common stock. The certification also confirms the holdings are not for changing or influencing control, aligning this with a passive institutional ownership posture.
What does Suvretta’s Schedule 13G/A filing say about its STRO ownership?
The filing shows Suvretta Capital Management, Averill Master Fund, and Aaron Cowen now report beneficial ownership of 0 Sutro Biopharma (STRO) shares, or 0% of the common stock. They report no sole or shared voting or dispositive power over any shares.
Who are the reporting persons in the Sutro Biopharma (STRO) Schedule 13G/A?
The reporting persons are Suvretta Capital Management, LLC, Averill Master Fund, Ltd., and Aaron Cowen. Each provides their citizenship and business addresses and collectively reports on ownership of Sutro Biopharma (STRO) common stock under the Schedule 13G/A amendment.
How many Sutro Biopharma (STRO) shares are beneficially owned by Suvretta and related filers?
Suvretta Capital Management, Averill Master Fund, and Aaron Cowen each report beneficial ownership of 0 Sutro Biopharma (STRO) shares. Correspondingly, they disclose 0% of the class and no sole or shared power to vote or dispose of any common stock shares.
What does ‘Ownership of 5 percent or less’ mean in the Sutro (STRO) filing?
The filing’s ‘Ownership of 5 percent or less’ disclosure indicates the reporting persons now hold less than 5% of Sutro Biopharma (STRO) common stock. They explicitly state that all securities referenced are owned by advisory clients, none exceeding the 5% beneficial ownership threshold.
Who directly owns the Sutro Biopharma (STRO) shares referenced in the Suvretta filing?
The filing states all securities referenced are directly owned by advisory clients of Suvretta Capital Management, LLC. It further notes that none of these advisory clients may be deemed to beneficially own more than 5% of Sutro Biopharma (STRO) common stock, $0.001 par value.
Does the Sutro Biopharma (STRO) 13G/A involve a change of control intent?
The certification states the securities were not acquired and are not held for changing or influencing control of Sutro Biopharma (STRO). It also clarifies they are not held in connection with any transaction intended to affect control, apart from certain nomination-related activities cited by rule.
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 13G
UNDER THE SECURITIES EXCHANGE ACT OF 1934
(Amendment No. 5)
Sutro Biopharma, Inc.
(Name of Issuer)
Common Stock, $0.001 par value
(Title of Class of Securities)
869367102
(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.
869367102
1
Names of Reporting Persons
SUVRETTA CAPITAL 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
0.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
0.00
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 %
12
Type of Reporting Person (See Instructions)
IA, OO
SCHEDULE 13G
CUSIP No.
869367102
1
Names of Reporting Persons
AVERILL MASTER FUND, LTD.
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
0.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
0.00
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 %
12
Type of Reporting Person (See Instructions)
CO
SCHEDULE 13G
CUSIP No.
869367102
1
Names of Reporting Persons
AARON COWEN
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
0.00
7
Sole Dispositive Power
0.00
8
Shared Dispositive Power
0.00
9
Aggregate Amount Beneficially Owned by Each Reporting Person
0.00
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 %
12
Type of Reporting Person (See Instructions)
HC, IN
SCHEDULE 13G
Item 1.
(a)
Name of issuer:
Sutro Biopharma, Inc.
(b)
Address of issuer's principal executive offices:
111 Oyster Point Blvd, South San Francisco, California, 94080
Item 2.
(a)
Name of person filing:
Suvretta Capital Management, LLC
Averill Master Fund, Ltd.
Aaron Cowen
(b)
Address or principal business office or, if none, residence:
Suvretta Capital Management, LLC
540 Madison Avenue, 7th Floor
New York, New York 10022
United States of America
Averill Master Fund, Ltd.
c/o Maples Corporate Services Limited
P.O. Box 309
Ugland House
Grand Cayman KY1-1104
Cayman Islands
Aaron Cowen
c/o Suvretta Capital Management, LLC
540 Madison Avenue, 7th Floor
New York, New York 10022
(c)
Citizenship:
Suvretta Capital Management, LLC - Delaware
Averill Master Fund, Ltd. - Cayman Islands
Aaron Cowen - United States
(d)
Title of class of securities:
Common Stock, $0.001 par value
(e)
CUSIP No.:
869367102
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).
Ownership of more than 5 Percent on Behalf of Another Person.
If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required.
All of the securities reported in this Schedule 13G are directly owned by advisory clients of Suvretta Capital Management, LLC. None of those advisory clients may be deemed to beneficially own more than 5% of the Common Stock, $0.001 par value.
Item 7.
Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
If a parent holding company has filed this schedule, pursuant to Rule 13d-1(b)(ii)(G), so indicate under Item 3(g) and attach an exhibit stating the identity and the Item 3 classification of the relevant subsidiary. If a parent holding company has filed this schedule pursuant to Rule 13d-1(c) or Rule 13d-1(d), attach an exhibit stating the identification of the relevant subsidiary.
Please see Exhibit B attached hereto.
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.
SUVRETTA CAPITAL MANAGEMENT, LLC
Signature:
By: /s/ Andrew Nathanson
Name/Title:
Andrew Nathanson, General Counsel and Chief Compliance Officer
Date:
02/13/2026
AVERILL MASTER FUND, LTD.
Signature:
By: /s/ Andrew Nathanson
Name/Title:
Andrew Nathanson, Authorized Signatory
Date:
02/13/2026
AARON COWEN
Signature:
By: /s/ Aaron Cowen
Name/Title:
Aaron Cowen
Date:
02/13/2026
Exhibit Information
[Exhibit A - Joint Filing Agreement]
[Exhibit B - Control Person Identification]
