Tectonic Therapeutic: Aberdeen reports 2.48% stake

Rhea-AI Filing Summary

Tectonic Therapeutic, Inc. common stock is the subject of an amended beneficial-ownership report by Aberdeen Group plc and abrdn Inc. Both report the same position of 484,887 shares, representing 2.48% of the class, with shared voting and shared dispositive power. abrdn Inc. states that it beneficially owns the shares on behalf of underlying clients.

Key Figures

Beneficial ownership: 484,887 shares Percent of class: 2.48% Shared voting and dispositive power: 484,887 shares

3 metrics

Beneficial ownership 484,887 shares Both reporting entities report the same position.

Percent of class 2.48% Reported by both reporting entities.

Shared voting and dispositive power 484,887 shares Reported by both reporting entities.

Key Terms

beneficially owned, Shared Voting Power, Shared Dispositive Power

3 terms

beneficially owned regulatory

"abrdn Inc. beneficially owns on behalf of our underlying clients"

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 Voting Power regulatory

"Shared Voting Power 484,887"

Shared voting power occurs when two or more parties jointly have the right to vote or decide how a block of company shares is cast, like co-owners who must agree before moving a piece of furniture. Investors care because who controls voting rights affects board elections, major corporate decisions and takeover outcomes, and shared control can alter regulatory disclosures and the practical influence any holder has over a company’s direction and value.

Shared Dispositive Power regulatory

"Shared Dispositive Power 484,887"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many TECX shares did Aberdeen report owning?

Aberdeen Group plc and abrdn Inc. each report the same position of 484,887 shares, equal to 2.48% of the class.

How are Aberdeen and abrdn Inc. related in the TECX ownership report?

Aberdeen Group plc is the parent company, and abrdn Holdings Limited is the intermediate holding company for abrdn Inc. abrdn Inc. states that it beneficially owns the shares on behalf of underlying clients.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 10/29/2026 - 10:58 AM EDT Accepted by SEC EDGAR 10/29/2026 - 10:57 AM EDT Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 1)

Tectonic Therapeutic, Inc.

(Name of Issuer)

Common Stock, $0.0001 par value per share

(Title of Class of Securities)

878972108

(CUSIP Number)

09/30/2026

(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): 878972108

1

Names of Reporting Persons

Aberdeen Group plc

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 KINGDOM

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 0.00
6	Shared Voting Power 484,887.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 484,887.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

484,887.00

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)

2.48 %

12

Type of Reporting Person (See Instructions)

HC

SCHEDULE 13G

CUSIP Number(s): 878972108

1

Names of Reporting Persons

abrdn Inc

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 484,887.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 484,887.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

484,887.00

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)

2.48 %

12

Type of Reporting Person (See Instructions)

CO, IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Tectonic Therapeutic, Inc.
(b)	Address of issuer's principal executive offices: 490 ARSENAL WAY, SUITE 210, WATERTOWN, MASSACHUSETTS 02472
Item 2.
(a)	Name of person filing: Aberdeen Group plc abrdn Inc
(b)	Address or principal business office or, if none, residence: 1 George Street Edinburgh, United Kingdom EH2 2LL abrdn Inc 1900 Market Street Suite 200. Philadelphia PA 19103
(c)	Citizenship: Aberdeen Group plc - UNITED KINGDOM abrdn Inc - UNITED STATES
(d)	Title of class of securities: Common Stock, $0.0001 par value per share
(e)	CUSIP No.: 878972108
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: 484,887
(b)	Percent of class: 2.48 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: Aberdeen Group plc - 0 abrdn Inc - 0
	(ii) Shared power to vote or to direct the vote: Aberdeen Group plc - 484,887 abrdn Inc - 484,887
	(iii) Sole power to dispose or to direct the disposition of: Aberdeen Group plc - 0 abrdn Inc - 0
	(iv) Shared power to dispose or to direct the disposition of: Aberdeen Group plc - 484,887 abrdn Inc - 484,887
Item 5.	Ownership of 5 Percent or Less of a Class.
	Ownership of 5 percent or less of a class
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.
	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. See Exhibit
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 acquired and are held in the ordinary course of business and 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.

Aberdeen Group plc

Signature:	R.Chaudhry
Name/Title:	Romiza Chaudhry / Major Shareholding Reporting Analyst
Date:	10/29/2026

abrdn Inc

Signature:	R.Chaudhry
Name/Title:	Romiza Chaudhry / Major Shareholding Reporting Analyst
Date:	10/29/2026

Exhibit Information

Aberdeen Group plc abrdn Holdings Limited abrdn Inc. Aberdeen Group plc is the parent company. abrdn Holdings Limited is the intermediate holding company for abrdn Inc. abrdn Inc. beneficially owns on behalf of our underlying clients less than 5% of the outstanding shares of the security class being reported on this Schedule 13G.