[Form 4/A] Trinseo PLC Amended Insider Trading Activity

Rhea-AI Filing Summary

Form 4/A overview: Trinseo PLC (TSE) director Jeffrey J. Cote reported an amended change in beneficial ownership dated 06/21/2025 and filed 06/27/2025. The sole reportable transaction is coded “F”, indicating shares were withheld to cover taxes upon vesting of previously granted restricted stock units and therefore not an open-market sale.

Key details

• 10,310 ordinary shares were withheld at a reference price of $3.73, reducing Mr. Cote’s direct holdings to 45,699 shares.
• The filing corrects the size of an indirect position held by the Cote 2019 Irrevocable Indenture Trust to 170,503 shares; no new transaction occurred for this block.
• Total beneficial ownership after the amendment equals 216,202 shares (direct + indirect).

Investor take-away: Because the F-code transaction is a routine tax-withholding event and the amendment merely restates indirect ownership, the filing carries minimal market impact. No purchase or discretionary sale was executed, and the insider remains a substantial shareholder.

Positive

• Director still holds approximately 216,202 shares, maintaining meaningful equity alignment with shareholders.
• Transaction coded 'F' denotes tax withholding, signalling that no discretionary selling pressure was applied to the market.

Negative

• 10,310 shares were removed from direct ownership, marginally reducing insider exposure.
• Need for an amendment highlights prior reporting inaccuracy, though it was promptly corrected.

Insights

Financial Analyst

TL;DR: Routine tax withholding; no open-market sale; negligible impact.

The sole F-coded entry reflects mandatory share withholding to satisfy tax obligations, a non-discretionary event that does not signal insider sentiment. The amendment’s only purpose is to correct the previously reported indirect share count, which now stands at 170,503 shares in a family trust. Post-adjustment, Cote retains more than 216k shares—evidence of continued alignment with shareholder interests. Given Trinseo’s average daily volume and market cap, disposal of 10k shares via withholding is immaterial. Overall, this Form 4/A is administratively necessary but not financially material to TSE valuation.

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^*

COTE JEFFREY J

(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)
06/24/2025

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		10,310(1)	D	$3.73	45,699	D
Ordinary Shares								170,503(2)	I(3)	By Cote 2019 Irrevocable Indenture Trust

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.

2. This amendment is being filed solely to correct the number of shares indirectly held by the reporting person.

3. Represents shares held by an irrevocable indenture trust having a disinterested trustee for the benefit of the reporting person and children (the "Cote 2019 Irrevocable Indenture Trust").

	/s/ Angelo Chaclas, Attorney-in-Fact	06/27/2025
	** 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 did Trinseo (TSE) insider Jeffrey Cote report in the Form 4/A?

He reported that 10,310 shares were withheld for taxes on 06/21/2025 and corrected indirect holdings to 170,503 shares.

Was the reported transaction an open-market sale?

No. It was an 'F' code transaction, meaning shares were withheld by the company to cover tax liabilities.

How many TSE shares does Cote own after the amendment?

45,699 directly and 170,503 indirectly, totaling 216,202 shares.

Does this filing indicate bullish or bearish insider sentiment?

Neither. Tax-related withholding is routine and does not reflect discretionary buying or selling.

Why was the Form 4 amended?

To correct the previously misstated number of indirectly held shares in the Cote 2019 Irrevocable Indenture Trust.