Verastem CFO Sells 55 Shares for Tax Withholding

Verastem, Inc. (VSTM) Chief Financial Officer Daniel Calkins reported a sale of 55 common shares on September 21, 2026, at $7.70 per share to satisfy statutory withholding requirements tied to restricted stock unit vesting.

Rhea-AI Filing Summary

Verastem, Inc. (VSTM) Chief Financial Officer Daniel Calkins reported a sale of 55 common shares on September 21, 2026, at $7.70 per share to satisfy statutory withholding requirements tied to restricted stock unit vesting. The transaction was made under a Rule 10b5-1 trading plan. Calkins directly beneficially owned 118,014 shares after the transaction; that total includes 831 shares acquired through Verastem’s 2018 Employee Stock Purchase Plan.

Insider Trade Summary 10b5-1

Net Seller: 55 shares

Net Sell 1 txn

Insider Calkins Daniel

Role Chief Financial Officer

Sold 55 shs ($423.50)

Type	Security	Shares	Price	Value
Sale	Common Stock F1, F2	55	$7.70	$423.50

Holdings After Transaction: Common Stock — 118,014 shares (Direct)

Footnotes (2)

1. F1. The sale reported on this Form 4 represents shares sold by the Reporting Person to satisfy statutory withholding requirements in connection with the vesting of restricted stock units.
2. F2. The total number of shares beneficially owned includes 831 shares of common stock acquired pursuant to the Issuer's 2018 Employee Stock Purchase Plan.

Key Figures

Common shares sold: 55 shares Price per share: $7.70 per share Shares beneficially owned after transaction: 118,014 shares +1 more

4 metrics

Common shares sold 55 shares September 21, 2026; to satisfy statutory withholding requirements tied to restricted stock unit vesting

Price per share $7.70 per share Sale on September 21, 2026

Shares beneficially owned after transaction 118,014 shares Directly owned following the September 21, 2026 transaction

Employee Stock Purchase Plan shares included 831 shares Included in shares beneficially owned

Key Terms

statutory withholding requirements, restricted stock units, Employee Stock Purchase Plan

3 terms

statutory withholding requirements financial

"to satisfy statutory withholding requirements"

restricted stock units financial

"in connection with the vesting of restricted stock units"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

Employee Stock Purchase Plan financial

"acquired pursuant to the Issuer's 2018 Employee Stock Purchase Plan"

An employee stock purchase plan is a company program that lets workers buy shares through small payroll deductions, often at a discount to the market price and after a set offering period. Think of it like a workplace savings plan that turns into ownership: it encourages employees to share in the company’s success and can create predictable buying or selling of stock that investors watch because it affects supply, demand and employee incentives.

FAQ

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How many VSTM shares did CFO Daniel Calkins sell, and at what price?

Daniel Calkins sold 55 common shares at $7.70 per share on September 21, 2026. The sale satisfied statutory withholding requirements in connection with restricted stock unit vesting and was made under a Rule 10b5-1 trading plan.

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

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Available on EDGAR 09/23/2026 - 08:10 PM Accepted by SEC EDGAR 09/23/2026 - 08:10 PM Learn about SEC filing dates

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

X

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Calkins Daniel

(Last) (First) (Middle)

C/O VERASTEM, INC.,

117 KENDRICK ST., SUITE 500

(Street)

NEEDHAM MASSACHUSETTS 02494

(City) (State) (Zip)

UNITED STATES

(Country)

2. Issuer Name and Ticker or Trading Symbol
Verastem, Inc. [ VSTM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Financial Officer

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/21/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/21/2026		S		55(1)	D	$7.7	118,014(2)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The sale reported on this Form 4 represents shares sold by the Reporting Person to satisfy statutory withholding requirements in connection with the vesting of restricted stock units.

2. The total number of shares beneficially owned includes 831 shares of common stock acquired pursuant to the Issuer's 2018 Employee Stock Purchase Plan.

	/s/ Daniel Calkins	09/23/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 4: SEC 1474 (03-26)