[Form 4] Trinseo PLC Insider Trading Activity

Rhea-AI Filing Summary

Form 4 snapshot: On 06/24/2025 Trinseo PLC (TSE) reported a 06/21/2025 insider transaction by director Matthew Farrell.

Key details

• Transaction code F – 9,576 ordinary shares automatically withheld to cover taxes at an implied $3.73 per share following the vesting of restricted stock units.
• Post-transaction holding – 107,741 directly owned shares; no derivative activity or indirect holdings reported.
• The 9,576 shares represent approximately 8% of the director’s pre-withholding position (117,317 shares) and did not involve an open-market decision or cash proceeds.

Interpretation – Code F events are routine, administrative and typically viewed as neutral because they do not reflect the insider’s sentiment toward the stock. The filing does not change Trinseo’s capital structure and provides no new information on operations, strategy or financial outlook.

Insights

Securities Analyst

TL;DR: Routine tax-withholding; 9.6k shares forfeited, ownership now 107.7k—no signal, neutral for valuation.

The filing discloses an F-code transaction, meaning the company withheld shares to satisfy Mr. Farrell’s tax liability after RSU vesting. Because the shares did not hit the open market and no discretionary sale occurred, the action is administrative. Farrell still holds over 100k shares, maintaining a sizeable alignment with shareholders. The 8% reduction in his stake is immaterial relative to Trinseo’s float and has no impact on liquidity, earnings or governance. Overall, investors should treat this as a housekeeping entry rather than a directional indicator.

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^*

FARRELL MATTHEW

(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
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
06/21/2025

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	06/21/2025		F		9,576(1)	D	$3.73	107,741	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	06/24/2025
	** 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

How many Trinseo (TSE) shares did Matthew Farrell dispose of on 06/21/2025?

He surrendered 9,576 ordinary shares to cover tax withholding.

What does transaction code F signify in this Form 4?

Code F indicates shares withheld by the issuer to pay taxes upon vesting of equity awards.

How many Trinseo shares does Farrell own after the transaction?

He directly owns 107,741 ordinary shares following the event.

Was this an open-market sale or purchase?

No. The shares were withheld internally; there was no open-market activity.

What was the implied price of the shares withheld?

The shares were valued at $3.73 per share according to the Form 4.