[Form 4] Trinseo PLC Insider Trading Activity

Rhea-AI Filing Summary

Trinseo PLC (TSE) – Form 4 Insider Transaction Summary

Director Joseph Alvarado reported the acquisition of 42,484 ordinary shares of Trinseo PLC on 25 June 2025. The transaction was coded “A,” indicating an award or grant, and was executed at a stated price of $0, confirming that the shares were received through an equity compensation plan rather than an open-market purchase.

The new shares were issued pursuant to a restricted stock unit (RSU) award that vests in full one year from the grant date. Following the grant, Alvarado’s total beneficial ownership increased to 94,671 shares, all of which are held directly. No derivative securities or additional transactions were reported.

This filing reflects routine director equity compensation designed to align management and shareholder interests. It does not disclose any open-market buying or selling activity, nor does it provide valuation details or earnings information. As such, the event is generally considered neutral to modestly positive for governance alignment but not financially material to the company’s overall share structure.

Positive

• Director increased direct ownership by 42,484 shares, enhancing management–shareholder alignment
• Grant vests in one year, supporting long-term governance incentives

Negative

• None.

Insights

Corporate Governance Specialist

TL;DR: Routine RSU grant; boosts alignment but minimal market impact.

The Form 4 shows that Director Joseph Alvarado received 42,484 RSUs, lifting his stake to 94,671 shares. Because the award vests in a year and was granted at no cost, it primarily serves as a long-term incentive, fostering board–shareholder alignment. No sales were disclosed, so there is no near-term supply pressure. The transaction is standard practice for S&P SmallCap firms and does not materially alter float or governance balance. Overall, I view it as a governance-friendly but non-impactful event for investors.

Portfolio Manager

TL;DR: Neutral; immaterial change to float, slight positive signal.

From a portfolio perspective, a 42.5k-share RSU grant is immaterial versus Trinseo’s total shares outstanding. However, insider acquisitions—even in the form of compensation—are generally preferable to disposals because they avoid negative signaling and mildly reinforce confidence. The lack of derivative exercises, sales, or 10b5-1 plan indicators suggests no immediate liquidity event. Given its limited scale and routine nature, I classify the filing as neutral for price discovery and do not adjust position sizing.

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^*

ALVARADO JOSEPH

(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	94,671	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. Represents ordinary shares issuable pursuant to a restricted stock unit award that will vest in full on the first anniversary of the grant date.

	/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 PLC (TSE) shares did Director Joseph Alvarado acquire?

He received 42,484 ordinary shares through an RSU grant.

What is Joseph Alvarado’s total Trinseo share ownership after the transaction?

His beneficial ownership increased to 94,671 shares.

Was the acquisition an open-market purchase?

No. The shares were granted at $0 price as part of an equity compensation plan.

When will the awarded RSUs vest?

The RSU award vests in full on the first anniversary of the 25 June 2025 grant date.

Did the filing report any derivative security transactions?

No derivative securities were acquired or disposed of in this Form 4.