Trinseo (NYSE: TSE) CEO reports tax-related share withholding

Rhea-AI Filing Summary

Trinseo PLC reported that CEO and President Frank A. Bozich had 23,680 Ordinary Shares withheld by the company at a price of $0.23 per share to cover taxes due upon the vesting of restricted stock units. Following this tax-withholding disposition, he directly holds 664,689 Ordinary Shares.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider BOZICH FRANK A

Role CEO AND PRESIDENT

Type	Security	Shares	Price	Value
Tax Withholding	Ordinary Shares	23,680	$0.23	$5K

Holdings After Transaction: Ordinary Shares — 664,689 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^*

BOZICH FRANK A

(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)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CEO AND PRESIDENT

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		23,680(1)	D	$0.23	664,689	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 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 CEO Frank A. Bozich?

Trinseo reported a tax-withholding disposition for CEO Frank A. Bozich. The company withheld 23,680 Ordinary Shares to satisfy taxes due when his restricted stock units vested, rather than an open-market purchase or sale.

How many Trinseo (TSE) shares were withheld for Frank A. Bozich’s taxes?

A total of 23,680 Trinseo Ordinary Shares were withheld to cover Frank A. Bozich’s tax obligations. This occurred in connection with the vesting of his restricted stock units, reflecting a standard equity compensation tax-settlement mechanism.

At what price were the Trinseo (TSE) shares valued for the CEO’s tax withholding?

The withheld Trinseo shares were valued at $0.23 per share for the tax-withholding disposition. This price is the transaction price per share used when the company retained shares to satisfy the CEO’s RSU-related tax liability.

How many Trinseo (TSE) shares does Frank A. Bozich hold after this transaction?

After the tax-withholding disposition, Frank A. Bozich directly holds 664,689 Trinseo Ordinary Shares. This figure reflects his remaining direct ownership following the company’s retention of shares to pay taxes on vested restricted stock units.

Was the Trinseo (TSE) CEO’s Form 4 transaction a market sale of shares?

The transaction was not an open-market sale. Shares were withheld by Trinseo to pay taxes owed when restricted stock units vested, described as a tax-withholding disposition rather than a discretionary buy or sell in the market.