Automatic tax-sale trims Karyopharm (NASDAQ: KPTI) EVP shareholdings

Rhea-AI Filing Summary

Karyopharm Therapeutics Inc. executive Stuart Poulton, EVP and Chief Development Officer, reported an automatic sale of common stock to cover taxes tied to restricted stock units that vested. On this transaction date, he sold 5,101 shares in an open-market sale at an average price of $9.4095 per share under a durable automatic sale instruction plan adopted on May 18, 2022. The filing states this broker-assisted sale was executed to satisfy withholding tax liabilities and did not represent a discretionary trade by Poulton. Following the sale, he directly held 94,328 shares of Karyopharm common stock.

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

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

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^*

Poulton Stuart

(Last) (First) (Middle)

C/O KARYOPHARM THERAPEUTICS INC.

85 WELLS AVENUE

(Street)

NEWTON MA 02459

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Karyopharm Therapeutics Inc. [ KPTI ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, Chief Development Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/02/2026

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

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

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

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	03/02/2026		S(1)		5,101	D	$9.4095	94,328	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. This transaction was effected pursuant to a durable automatic sale instruction plan adopted by the reporting person on May 18, 2022, and represents a broker-assisted sale of shares to satisfy the payment of withholding tax liability incurred upon the vesting of restricted stock units. The sale does not represent a discretionary trade by the reporting person.

	/s/ Nancy Smith as Attorney-in-Fact for Stuart Poulton	03/03/2026
	** 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).
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FAQ

What insider transaction did Karyopharm (KPTI) report for Stuart Poulton?

Karyopharm reported that EVP and Chief Development Officer Stuart Poulton sold 5,101 shares of common stock. The shares were sold in an open-market, broker-assisted transaction specifically to cover withholding taxes arising from restricted stock units that had recently vested.

At what price were Stuart Poulton’s Karyopharm (KPTI) shares sold?

The 5,101 Karyopharm shares sold for an average price of $9.4095 per share. This sale was executed as part of a broker-assisted process under an automatic instruction plan to satisfy tax withholding obligations from vested restricted stock units.

How many Karyopharm (KPTI) shares does Stuart Poulton hold after this Form 4?

After the reported sale, Stuart Poulton directly holds 94,328 shares of Karyopharm common stock. The Form 4 indicates that only 5,101 shares were sold and clarifies the remaining direct ownership following the tax-related, automatic sale transaction.

Was Stuart Poulton’s Karyopharm (KPTI) share sale a discretionary trade?

The sale was not a discretionary trade by Stuart Poulton. A footnote explains it was executed under a durable automatic sale instruction plan and completed by a broker solely to cover tax withholding from the vesting of restricted stock units.

Why did Karyopharm EVP Stuart Poulton sell shares according to the Form 4?

The Form 4 explains that Stuart Poulton’s sale was to satisfy withholding tax liability triggered when restricted stock units vested. A broker sold 5,101 shares under a pre-established automatic sale plan, rather than through a discretionary decision by the executive.