[Form 4] Trinseo PLC Insider Trading Activity

Rhea-AI Filing Summary

Trinseo PLC (TSE) – Form 4 insider filing

Director Jeffrey J. Cote reported a change in beneficial ownership effective 25 June 2025. The filing discloses:

• 42,484 ordinary shares were acquired through a restricted stock unit (RSU) grant that vests in full on the first anniversary of the grant date. The grant price is listed as $0 because RSUs are issued without cash consideration.
• Following the award, Cote directly owns 88,183 ordinary shares and indirectly controls 170,503 shares held by the “Cote 2019 Irrevocable Indenture Trust” for the benefit of himself and his children.
• No derivative securities transactions were reported for the period.

The filing is single-party, routine in nature, and does not reference any sales, option exercises, or 10b5-1 trading plans.

Insights

Corporate Governance Analyst

TL;DR: Routine RSU grant; neutral governance signal.

The Form 4 reflects a standard annual equity award to an outside director, consistent with typical board compensation practices. The addition of 42,484 RSUs modestly increases insider alignment but does not signal incremental buying conviction because no cash was deployed. Total direct and indirect holdings now stand at 258,686 shares, but the company did not disclose percentage ownership, making it difficult to gauge relative stake size. There are no sales or derivative conversions, so the filing lacks negative implications. Overall, this is an ordinary administrative disclosure with negligible impact on valuation or governance risk.

Portfolio Manager

TL;DR: No trading signal; immaterial to investment thesis.

From a portfolio perspective, an RSU award at $0 does not constitute open-market buying and thus carries little informational value. The quantity—≃42 k shares—appears minor relative to Trinseo’s 34 million-plus shares outstanding, implying <0.15% dilution. Because there were no dispositions, the filing is not a red flag, but it also doesn’t strengthen a bull case. I classify the market impact as de minimis; no portfolio adjustment is warranted.

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)
06/25/2025

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	06/25/2025		A		42,484(1)	A	$0	88,183	D
Ordinary Shares								170,503	I(2)	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. Represents ordinary shares issuable pursuant to a restricted stock unit award that will vest in full on the first anniversary of the grant date.

2. 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

How many Trinseo (TSE) shares did director Jeffrey Cote acquire on 25 June 2025?

He received 42,484 ordinary shares via a restricted stock unit award.

Does the Form 4 show any sale of Trinseo shares by the director?

No. The filing reports only an acquisition; there were no sales or dispositions of shares.

What is the director’s total direct ownership after the RSU grant?

Jeffrey Cote directly owns 88,183 ordinary shares following the transaction.

How many Trinseo shares are held indirectly through the Cote 2019 Irrevocable Indenture Trust?

The trust holds 170,503 shares for the benefit of Cote and his children.

When will the newly granted RSUs vest?

The RSUs will vest in full on the first anniversary of the grant date.