Arlene Morris - 27 Aug 2026 Form 4 Insider Report for Cogent Biosciences, Inc. (COGT)

Reporting relationship: Director
Issuer ticker: COGT
Reported as of: 27 Aug 2026
Net transaction value: -$1,689,493
SEC form: 4
Accepted by SEC: 31 Aug 2026, 17:01:57 UTC
Prior SEC filing: 05 Aug 2026
Source filing: View source filing
Reporting owner signature: /s/ Evan D. Kearns, Attorney-in-Fact

Key filing fact

Arlene Morris filed Form 4 for Cogent Biosciences, Inc. (COGT) on 31 Aug 2026.

Key facts

This page summarizes Arlene Morris's Form 4 filing for Cogent Biosciences, Inc. (COGT).
6 reported transactions and 2 derivative rows are listed below.
Accepted by SEC: 31 Aug 2026, 17:01.

Change

Previous filing in this sequence was filed on 05 Aug 2026.
Current net transaction value: -$1,689,493.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001362520 Primary reporting owner

Morris Arlene

Relationship: Director
Address: C/O COGENT BIOSCIENCES, INC., 180 THIRD AVENUE, 4TH FLOOR, WALTHAM
Signature: /s/ Evan D. Kearns, Attorney-in-Fact
Signature date: 31 Aug 2026

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

COGT transaction

Common Stock

Options Exercise

Transaction value
Shares: +41,927
Change %
Price: $5.64^*
Shares after: 41,927
Date: 27 Aug 2026
Ownership: Direct
Footnotes: F1

COGT transaction

Common Stock

Options Exercise

Transaction value
Shares: +3,583
Change %: +8.5%
Price: $2.52^*
Shares after: 45,510
Date: 27 Aug 2026
Ownership: Direct
Footnotes: F1

COGT transaction

Common Stock

Sale

Transaction value: $1,570,830
Shares: -42,349
Change %: -93%
Price: $37.09
Shares after: 3,161
Date: 27 Aug 2026
Ownership: Direct
Footnotes: F1, F2

COGT transaction

Common Stock

Sale

Transaction value: $118,663
Shares: -3,161
Change %: -100%
Price: $37.54
Shares after: 0
Date: 27 Aug 2026
Ownership: Direct
Footnotes: F1, F3

Reported derivative securities

Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.

COGT transaction Derivative

Stock Option (Right to Buy)

Options Exercise

Transaction value
Shares: -41,927
Change %: -94%
Price: $0.000000^*
Shares after: 2,773
Date: 27 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 41,927
Exercise price: $5.64
Footnotes: F1, F4

COGT transaction Derivative

Stock Option (Right to Buy)

Options Exercise

Transaction value
Shares: -3,583
Change %: -100%
Price: $0.000000^*
Shares after: 0
Date: 27 Aug 2026
Ownership: Direct
Underlying class: Common Stock
Underlying amount: 3,583
Exercise price: $2.52
Footnotes: F1, F4

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Rule 10b5-1 trading plan

These transactions were reported as open-market trades under a Rule 10b5-1 plan. The plan lets an insider set trading instructions in advance, which can reduce the risk of trading while in possession of material nonpublic information.

Original filing language: transaction made pursuant to a contract, instruction, or written plan intended to satisfy Rule 10b5-1(c).

Explanation of responses 4 footnotes

Footnote F1

Transactions effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on May 28, 2026.

Footnote F2

The price reported represents the weighted average sale price per share. The shares were sold in multiple transactions at prices ranging from $36.46 to $37.45. Upon request by the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

Footnote F3

The price reported represents the weighted average sale price per share. The shares were sold in multiple transactions at prices ranging from $37.46 to $37.65. Upon request by the staff of the U.S. Securities and Exchange Commission, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

Footnote F4

These options are fully vested.