[144] Tango Therapeutics, Inc. SEC Filing

Rhea-AI Filing Summary

Tango Therapeutics, Inc. (TNGX) filed a Form 144 reporting a proposed sale of 642,906 common shares through broker BTIG, LLC, with an aggregate market value of $4,461,767 and an indicated approximate sale date of 09/05/2025. The filing shows the shares were originally acquired as a pre-IPO investment on 03/23/2017 and payment for that acquisition was by wire. The filing also discloses sales by Third Rock Ventures IV, L.P. totaling 1,402,194 shares in August 2025 for combined gross proceeds of $9,425,118. The notice includes the standard representation that the seller is not aware of undisclosed material adverse information.

Positive

• Compliance with Rule 144: The filing provides required notice and provenance for the shares, demonstrating regulatory transparency.
• Clear acquisition history: The shares were acquired as a pre-IPO investment on 03/23/2017, with payment method documented as wire.

Negative

• Recent substantial secondary sales: Third Rock Ventures IV sold 1,402,194 shares in August 2025 for $9,425,118, increasing available supply from early investors.
• Potential shareholder turnover: Combined recent and proposed sales represent a noticeable transfer of ownership that could affect trading supply and investor composition.

Insights

Securities Analyst

TL;DR The filing documents an orderly disposition of pre-IPO holdings and recent large secondary sales, a routine liquidity event rather than an operational disclosure.

The Form 144 shows a proposed sale of 642,906 shares valued at $4.46 million and prior August 2025 dispositions by a related investor totaling 1,402,194 shares for $9.43 million. For investors, these are liquidity transactions by early investors rather than new company developments. The size of the aggregated August sales represents roughly 1.26% of the reported 111,260,247 shares outstanding, indicating meaningful but not overwhelming secondary-market supply. The filing follows Rule 144 disclosure requirements and provides clear provenance of the shares as a 2017 pre-IPO investment.

Corporate Governance Expert

TL;DR Disclosure complies with Rule 144 and signals investor exits; governance impact is limited absent additional context.

The filer certifies no undisclosed material adverse information and documents the broker and mechanics of the proposed sale. The concurrent August 2025 sales by Third Rock Ventures IV, L.P. show significant insider liquidity occurred recently. From a governance standpoint, these transactions are standard for early investors seeking liquidity and do not by themselves indicate governance changes or new material risks, but they are relevant to shareholder base turnover and voting composition.

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK
Filer CCC
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer

SEC File Number

Address of Issuer

Phone

Name of Person for Whose Account the Securities are To Be Sold

See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.

Relationship to Issuer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	BTIG, LLC 350 Bush Street 9th Floor San Francisco CA 94104	642906	4461767.00	111260247	09/05/2025	NASDAQ GM

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
common	03/23/2017	Pre-IPO investment	Tango Therapeutics Inc			642906	03/23/2017	Wire

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
Third Rock Ventures IV, L.P. 201 BROOKLINE AVENUE Suite 1401 BOSTON MA 02215	common	08/19/2025	1100000	7712760.00
Third Rock Ventures IV, L.P. 201 BROOKLINE AVENUE Suite 1401 BOSTON MA 02215	common	08/22/2025	302194	2115358.00

144: Remarks and Signature

Remarks

Date of Notice

ATTENTION:

The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.

Signature

ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)

FAQ

What does Tango Therapeutics' Form 144 filing disclose about the proposed sale?

The filing reports a proposed sale of 642,906 common shares via BTIG with an aggregate market value of $4,461,767 and an approximate sale date of 09/05/2025.

Who originally acquired the shares being sold and when?

The shares were acquired as a pre-IPO investment on 03/23/2017 from Tango Therapeutics Inc, with payment by wire.

Did any related parties sell Tango shares recently?

Yes. Third Rock Ventures IV, L.P. sold 1,100,000 shares on 08/19/2025 for $7,712,760 and 302,194 shares on 08/22/2025 for $2,115,358.

How large are these sales relative to outstanding shares?

The filing reports 111,260,247 shares outstanding; the proposed 642,906-share sale and the August 2025 sales together represent a modest percentage of that total.

Does the filer state there is any undisclosed material information?

By signing the notice, the person represents they do not know any material adverse information about the issuer that has not been publicly disclosed.