Trinseo (TSE) CFO Stasse has shares withheld to cover RSU taxes

Rhea-AI Filing Summary

Trinseo PLC executive David Phillip Stasse reported a tax-related share disposition. On the tax-withholding date of vesting for previously granted restricted stock units, 10,366 Ordinary Shares were withheld by the company at a price of $0.23 per share to cover taxes. After this tax-withholding disposition, Stasse directly owned 254,788 Ordinary Shares.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider Stasse David Phillip

Role EVP AND CFO

Type	Security	Shares	Price	Value
Tax Withholding	Ordinary Shares	10,366	$0.23	$2K

Holdings After Transaction: Ordinary Shares — 254,788 shares (Direct)

Footnotes (1)

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Form 4 Insider Transactions: What Each Field Means →

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).

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^*

Stasse David Phillip

(Last) (First) (Middle)

C/O TRINSEO PLC

440 EAST SWEDESFORD ROAD, SUITE 301

(Street)

WAYNE PA 19087

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Trinseo PLC [ TSE ]

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

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP AND CFO

3. Date of Earliest Transaction (Month/Day/Year)
02/27/2026

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
Ordinary Shares	02/27/2026		F		10,366(1)	D	$0.23	254,788	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. Shares withheld by the Company to pay taxes due following the vesting of previously granted restricted stock units.

	/s/ Angelo Chaclas, Attorney-in-Fact	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).
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.

FAQ

What insider transaction did Trinseo (TSE) report for David Phillip Stasse?

Trinseo reported a tax-withholding disposition for EVP and CFO David Phillip Stasse. The company withheld 10,366 Ordinary Shares upon vesting of restricted stock units to pay taxes due, rather than an open-market sale or purchase.

How many Trinseo (TSE) shares were disposed of in this Form 4 filing?

The filing shows 10,366 Ordinary Shares were disposed of. These shares were withheld by Trinseo to satisfy tax obligations arising from the vesting of previously granted restricted stock units, according to the accompanying footnote disclosure.

At what price were the Trinseo (TSE) shares valued for this tax withholding?

The 10,366 Ordinary Shares were valued at $0.23 per share for the tax-withholding disposition. This price is used in the Form 4 to calculate the value of shares withheld to cover the executive’s tax liability on vesting.

Does David Phillip Stasse still hold Trinseo (TSE) shares after this transaction?

Yes. After the tax-withholding disposition, David Phillip Stasse directly held 254,788 Ordinary Shares. This figure reflects his ownership following the company’s withholding of 10,366 shares to satisfy taxes on vested restricted stock units.

Was the Trinseo (TSE) insider transaction an open-market sale or a tax withholding?

The transaction was a tax withholding, not an open-market sale. The Form 4 footnote explains that shares were withheld by Trinseo to pay taxes due upon vesting of previously granted restricted stock units awarded to the executive.

What role does David Phillip Stasse hold at Trinseo (TSE) in this Form 4?

David Phillip Stasse is identified as Executive Vice President and Chief Financial Officer. The Form 4 reports his tax-withholding disposition of Trinseo Ordinary Shares related to the vesting of earlier granted restricted stock unit awards.