TNGX Notice: Insider Sale of 500K Shares via BTIG on 09/25/2025

Rhea-AI Filing Summary

Tango Therapeutics, Inc. (TNGX) Form 144 reports a proposed sale of 500,000 shares of common stock through BTIG, LLC on 09/25/2025 with an aggregate market value of $3,900,000.00. The shares were originally acquired on 07/24/2017 as a pre-IPO investment from Tango Therapeutics, Inc., and payment was by wire. The filing also discloses multiple recent sales by Third Rock Ventures IV, L.P. during Aug–Sep 2025 totaling several transactions of common stock with gross proceeds reported for each sale.

Positive

• Planned sale documented under Rule 144 showing procedural compliance
• Long-held pre-IPO acquisition (07/24/2017) indicates shares originated from an early investor
• Use of a broker (BTIG, LLC) suggests an orderly execution channel for the sale

Negative

• Multiple large dispositions by Third Rock Ventures IV, L.P. in Aug–Sep 2025 could increase public float and selling pressure
• Significant gross proceeds reported across recent transactions, indicating meaningful realized liquidity by a major holder

Insights

Securities Analyst

TL;DR: Routine officer/shareholder resale notice; recent large secondary sales by a major holder could increase public float.

The Form 144 documents a notice of proposed sale under Rule 144 for 500,000 shares valued at $3.9M to be executed through a broker on 09/25/2025. The securities were originally a pre-IPO holding from 2017, indicating long-term ownership. The filing itself is procedural, but the accompanying disclosures show multiple sizeable dispositions by Third Rock Ventures IV, L.P. in Aug–Sep 2025 with material gross proceeds reported, which may meaningfully increase shares available to the market and affect supply dynamics in the near term.

Corporate Governance Expert

TL;DR: Disclosure aligns with Rule 144 requirements; represents liquidity events for early investors.

The notice indicates compliance with Rule 144 procedures for a planned sale and includes the seller's representation regarding material nonpublic information. The historical acquisition as a pre-IPO investment and payment method by wire are documented. Multiple recent sales by a related investor group suggest staged liquidity execution rather than a single block sale, a common governance outcome for venture-backed exits.

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	500000	3900000.00	111260247	09/25/2025	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	07/24/2017	Pre-IPO investment	Tango Therapeutics Inc			500000	07/24/2017	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	2115358.00
Third Rock Ventures IV, L.P. 201 BROOKLINE AVENUE Suite 1401 BOSTON MA 02215	Common	08/22/2025	302194	2103270.24
Third Rock Ventures IV, L.P. 201 BROOKLINE AVENUE suite 1401 BOSTON MA 02215	Common	09/05/2025	642906	4500342.00
Third Rock Ventures IV, L.P. 201 BROOKLINE AVENUE Suite 1401 BOSTON MA 02215	Common	09/08/2025	86459	2557620.00
Third Rock Ventures IV, L.P. 201 BROOKLINE AVENUE, Suite 1401 BOSTON MA 02215	Common	09/16/2025	363541	2557620.00

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 the Form 144 filed for TNGX disclose?

The filing discloses a proposed sale of 500,000 common shares via BTIG, LLC on 09/25/2025 valued at $3,900,000.00.

When and how were the shares being sold acquired?

The shares were acquired on 07/24/2017 as a pre-IPO investment from Tango Therapeutics, Inc., with payment noted as wire.

Who has sold Tango Therapeutics shares recently according to the filing?

The filing lists multiple recent sales by Third Rock Ventures IV, L.P. during Aug–Sep 2025, with each sale's gross proceeds reported.

How much value is the proposed 500,000-share sale estimated at?

The aggregate market value reported for the 500,000 shares is $3,900,000.00.

Does the filer state any material nonpublic information concerns?

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