Form 4: Insider Tax Withholding at Trinseo Leaves 48k Shares Held

Rhea-AI Filing Summary

SEC Form 4 snapshot: Trinseo PLC (TSE) director K. Lynne Johnson reported a disposal of 10,474 ordinary shares on 06/21/2025. The shares were withheld by the company at $3.73 per share to satisfy tax obligations tied to the vesting of previously granted restricted stock units (transaction code “F”).

After the tax-related withholding, Johnson’s direct ownership stands at 48,429 ordinary shares. No derivative securities or Rule 10b5-1 trading plan were disclosed.

Because “F”-coded transactions reflect mandatory tax settlements rather than discretionary trading, the filing is generally viewed as neutral with minimal impact on insider sentiment or valuation outlook.

Insights

Securities Analyst

TL;DR: Routine tax-withholding disposition; insider still owns 48k shares—neutral to sentiment.

The Form 4 registers a non-discretionary, code “F” share disposition. Such transactions do not signal confidence or concern; they merely settle payroll taxes after RSU vesting. Johnson’s post-event stake (48,429 shares) remains material, indicating continued alignment with shareholders. There are no derivative positions or 10b5-1 plans that could alter this interpretation. Given the small absolute value and the administrative nature, I rank the impact as neutral.

Corporate Governance Expert

TL;DR: Compliance filing shows proper tax handling; no governance red flags.

The company correctly withheld shares to cover statutory taxes, reducing cash outlay for the director and maintaining transparency under Section 16. Absence of derivative transactions and unchanged overall ownership mitigate any perception of aggressive trading. Governance processes appear intact, and the filing meets timeliness requirements. Investors should not infer strategic intent from this action.

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^*

Johnson KLynne

(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		10,474(1)	D	$3.73	48,429	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

What insider activity did Trinseo (TSE) report in the latest Form 4?

Director K. Lynne Johnson had 10,474 shares withheld to pay taxes on vested RSUs.

When did the Trinseo insider transaction occur?

The transaction date was June 21, 2025.

How many Trinseo shares does Johnson own after the transaction?

She now directly owns 48,429 ordinary shares.

Was the transaction an open-market sale?

No. It was a code “F” tax-withholding event, not a discretionary sale.

At what price were the shares valued for withholding purposes?

The shares were valued at $3.73 apiece.

Did the filing list any derivative securities?

No derivative securities were reported.