Adage Capital discloses 3.44% Tango Therapeutics (TNGX) stake in 13G/A filing

Rhea-AI Filing Summary

Adage Capital Management, L.P. and related parties report beneficial ownership of Tango Therapeutics, Inc. common stock. Adage Capital Management, Robert Atchinson, and Phillip Gross collectively report beneficial ownership of 5,600,000 shares of common stock, representing 3.44% of the class. All 5,600,000 shares are reported with shared voting and shared dispositive power, and no sole voting or dispositive power. The percentage is based on 162,814,649 shares outstanding, consisting of 18,166,667 shares offered under a June 10, 2026 prospectus and 144,647,982 shares outstanding as of May 6, 2026. The filing indicates ownership of 5 percent or less of Tango’s common stock.

Key Figures

Shares beneficially owned: 5,600,000 shares Percent of class: 3.44% Shares outstanding baseline: 162,814,649 shares +4 more

7 metrics

Shares beneficially owned 5,600,000 shares Common Stock of Tango Therapeutics reported by the Reporting Persons

Percent of class 3.44% Beneficial ownership percentage of Tango Therapeutics common stock

Shares outstanding baseline 162,814,649 shares Total Tango Therapeutics shares used to calculate ownership percentage

Prospectus offering shares 18,166,667 shares Common Stock offered under Rule 424(b)(5) prospectus filed June 10, 2026

Shares outstanding as of May 6, 2026 144,647,982 shares Tango Therapeutics common stock outstanding from Form 10-Q

Shared voting power 5,600,000 shares Shares over which the Reporting Persons have shared voting power

Sole voting power 0 shares Shares over which the Reporting Persons have sole voting power

Key Terms

beneficial ownership, shared voting power, shared dispositive power, percent of class, +1 more

5 terms

beneficial ownership financial

"The filing of this statement should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership"

Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.

shared voting power financial

"Shared Voting Power 5,600,000.00"

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 financial

"Shared Dispositive Power 5,600,000.00"

percent of class financial

"Percent of class: 3.44%"

Percent of class is the portion of a specific category of securities—such as a company’s common shares, preferred shares, or a bond series—that takes part in or approves a corporate action (vote, consent, tender, etc.). Investors watch this number because it reveals how much support or opposition exists within that particular shareholder group; like counting how many members of a club back a proposal, it can determine whether a plan passes or how influence is distributed.

Investment Adviser financial

"12 IA,"

An investment adviser is a person or firm that professionally manages money and gives recommendations about buying, selling, or holding investments. Like a financial coach or guide, they have a legal duty to act in a client's best financial interest, so their advice, fees and potential conflicts can directly affect returns and risk — making their role important for investors who want informed, accountable help with portfolios.

FAQ

How many Tango Therapeutics (TNGX) shares does Adage Capital report owning?

Adage Capital and the related reporting persons report beneficial ownership of 5,600,000 shares of Tango Therapeutics common stock, all held with shared voting and shared dispositive power through Adage Capital Partners, L.P.

What percentage of Tango Therapeutics (TNGX) does Adage Capital currently own?

The reporting persons state they beneficially own 3.44% of Tango Therapeutics’ common stock. This percentage is calculated using a total of 162,814,649 shares of common stock outstanding, as described in the ownership section.

How many Tango Therapeutics (TNGX) shares are outstanding for this 13G/A calculation?

The ownership calculation uses 162,814,649 Tango Therapeutics common shares outstanding, comprising 18,166,667 shares offered under a June 10, 2026 prospectus and 144,647,982 shares outstanding as of May 6, 2026.

Do Adage Capital and its principals have sole or shared voting power in TNGX?

The reporting persons disclose 0 shares with sole voting power and 5,600,000 shares with shared voting power. They likewise report 0 shares with sole dispositive power and 5,600,000 shares with shared dispositive power.

Does this Schedule 13G/A show Adage Capital over or under 5% of TNGX?

The Schedule 13G/A indicates ownership of 5 percent or less of Tango Therapeutics’ common stock. Specifically, the reported beneficial ownership is 3.44% of the outstanding common shares.

Who are the reporting persons in the Tango Therapeutics (TNGX) Schedule 13G/A?

The filing identifies Adage Capital Management, L.P., and individuals Robert Atchinson and Phillip Gross as the reporting persons, relating to shares directly held by Adage Capital Partners, L.P.

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Available on EDGAR 08/12/2026 - 12:02 PM Accepted by SEC EDGAR 08/12/2026 - 12:01 PM Learn about SEC filing dates

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 2)

Tango Therapeutics, Inc.

(Name of Issuer)

Common Stock, par value $0.001 per share

(Title of Class of Securities)

87583X109

(CUSIP Number)

06/30/2026

(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): 87583X109

1

Names of Reporting Persons

Adage Capital Management, L.P.

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 5,600,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,600,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,600,000.00

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)

3.44 %

12

Type of Reporting Person (See Instructions)

IA, PN

SCHEDULE 13G

CUSIP Number(s): 87583X109

1

Names of Reporting Persons

Robert Atchinson

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 5,600,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,600,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,600,000.00

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)

3.44 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

CUSIP Number(s): 87583X109

1

Names of Reporting Persons

Phillip Gross

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 5,600,000.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 5,600,000.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

5,600,000.00

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)

3.44 %

12

Type of Reporting Person (See Instructions)

HC, IN

SCHEDULE 13G

Item 1.
(a)	Name of issuer: Tango Therapeutics, Inc.
(b)	Address of issuer's principal executive offices: 201 Brookline Avenue, Suite 901, Boston, MA 02215 02215
Item 2.
(a)	Name of person filing: This statement is filed by: (i) Adage Capital Management, L.P., a Delaware limited partnership ("ACM"), as the investment manager of Adage Capital Partners, L.P., a Delaware limited partnership ("ACP"), with respect to the common stock, par value $0.001 per share ("Common Stock"), of Tango Therapeutics, Inc., a Delaware corporation (the "Company"), directly held by ACP; (ii) Robert Atchinson ("Mr. Atchinson"), as (1) managing member of Adage Capital Advisors, L.L.C., a limited liability company organized under the laws of the State of Delaware ("ACA"), managing member of Adage Capital Partners GP, L.L.C., a limited liability company organized under the laws of the State of Delaware ("ACPGP"), general partner of ACP and (2) managing member of Adage Capital Partners LLC, a Delaware limited liability company ("ACPLLC"), general partner of ACM, with respect to the Common Stock directly held by ACP; and (iii) Phillip Gross ("Mr. Gross"), as (1) managing member of ACA, managing member of ACPGP and (2) managing member of ACPLLC, general partner of ACM, with respect to the Common Stock directly held by ACP. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." Any disclosures herein with respect to persons other than the Reporting Persons are made on information and belief after making inquiry to the appropriate party. The filing of this statement should not be construed in and of itself as an admission by any Reporting Person as to beneficial ownership of the securities reported herein.
(b)	Address or principal business office or, if none, residence: The address of the business office of each of the Reporting Persons is 200 Clarendon Street, 52nd Floor, Boston, Massachusetts 02116.
(c)	Citizenship: ACM is a limited partnership organized under the laws of the State of Delaware. Messrs. Gross and Atchinson are citizens of the United States.
(d)	Title of class of securities: Common Stock, par value $0.001 per share
(e)	CUSIP No.: 87583X109
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: The information required by Item 4(a) is set forth in Row 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. The percentage set forth in this Schedule 13G is calculated based upon an aggregate of 162,814,649 Common Stock outstanding, which is the sum of (i) the 18,166,667 Common Stock offered pursuant to the Company's Prospectus filed pursuant to Rule 424(b)(5) with the Securities and Exchange Commission (the "SEC") on June 10, 2026 and (ii) the 144,647,982 shares of Common Stock outstanding as of May 6, 2026, as reported in the Company's Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2026 filed with the SEC on May 13, 2026.
(b)	Percent of class: 3.44%
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: The information required by Item 4(c)(i) is set forth in Row 5 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(ii) Shared power to vote or to direct the vote: The information required by Item 4(c)(ii) is set forth in Row 6 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(iii) Sole power to dispose or to direct the disposition of: The information required by Item 4(c)(iii) is set forth in Row 7 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
	(iv) Shared power to dispose or to direct the disposition of: The information required by Item 4(c)(iv) is set forth in Row 8 of the cover page for each of the Reporting Persons and is incorporated herein by reference.
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.
	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. See Item 2(a).
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 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.

Adage Capital Management, L.P.

Signature:	/s/ Robert Atchinson
Name/Title:	By: Adage Capital Partners LLC, its General Partner, By: Robert Atchinson, its Managing Member
Date:	08/12/2026

Robert Atchinson

Signature:	/s/ Robert Atchinson
Name/Title:	Robert Atchinson, individually
Date:	08/12/2026

Phillip Gross

Signature:	/s/ Phillip Gross
Name/Title:	Phillip Gross, individually
Date:	08/12/2026