Trinseo (TSE) director Joseph Alvarado forfeits 42,484 RSUs, holds 52,187 shares

Rhea-AI Filing Summary

Trinseo PLC director Joseph Alvarado reported a voluntary forfeiture of equity awards. The Form 4 shows an "other" transaction involving 42,484 Ordinary Shares at a stated price of $0.00 per share, tied to restricted stock units (RSUs) previously granted on June 25, 2025.

The footnote explains this reflects a voluntary forfeiture of RSUs that had not yet vested or settled, rather than an open-market trade. Following this restructuring-type adjustment, Alvarado is reported as directly holding 52,187 Ordinary Shares.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider ALVARADO JOSEPH

Role null

Type	Security	Shares	Price	Value
Other	Ordinary Shares	42,484	$0.00	--

Holdings After Transaction: Ordinary Shares — 52,187 shares (Direct, null)

Footnotes (1)

1. [object Object]

Key Figures

Restructuring shares: 42,484 shares Transaction price: $0.00 per share Shares held after: 52,187 shares +1 more

4 metrics

Restructuring shares 42,484 shares Shares linked to forfeited RSUs in J-code transaction

Transaction price $0.00 per share Reported price for the J-code "other" transaction

Shares held after 52,187 shares Ordinary Shares directly owned after the transaction

Restructuring share count 42,484 shares RestructuringShares in transaction summary

Key Terms

restricted stock units, voluntary forfeiture, restructuring, Ordinary Shares

4 terms

restricted stock units financial

"Reflects a voluntary forfeiture by the Reporting Person of restricted stock units ("RSUs")"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

voluntary forfeiture financial

"Reflects a voluntary forfeiture by the Reporting Person of restricted stock units"

restructuring financial

"restructuringCount": 1, "restructuringShares": 42484"

Restructuring is a deliberate rearrangement of a company’s operations, finances, or ownership—like reorganizing a cluttered house to run more efficiently—often involving cost cuts, asset sales, debt changes, or staff moves. Investors pay attention because restructuring can improve profitability and free up cash, but it can also signal distress, incur one-time costs, or dilute shareholder value; its success affects future earnings and stock performance.

Ordinary Shares financial

"security_title": "Ordinary Shares""

Ordinary shares are a type of ownership stake in a company, giving shareholders a right to participate in the company’s profits and decision-making through voting. They are similar to owning a piece of a business, and their value can rise or fall based on the company's performance. Investors buy ordinary shares to potentially earn dividends and benefit from the company's growth over time.

Form 4 Insider Transactions: What Each Field Means →

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 PENNSYLVANIA 19087

(City) (State) (Zip)

UNITED STATES

(Country)

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)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/12/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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	05/12/2026		J(1)		42,484	D	(1)	52,187	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. Reflects a voluntary forfeiture by the Reporting Person of restricted stock units ("RSUs") that were previously granted on June 25, 2025. At the time of forfeiture, the RSU award was not vested or settled, in full or in part.

	/s/ Angelo Chaclas, Attorney-in-Fact	05/14/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What insider transaction did Trinseo (TSE) director Joseph Alvarado report?

Joseph Alvarado reported an "other" transaction on Trinseo stock involving 42,484 Ordinary Shares. A footnote clarifies this reflects a voluntary forfeiture of previously granted restricted stock units that had not vested or settled, rather than a market purchase or sale.

Did Joseph Alvarado buy or sell Trinseo (TSE) shares in this Form 4?

The filing does not show a traditional buy or sell. It records an "other" restructuring transaction linked to a voluntary forfeiture of 42,484 unvested restricted stock units, with no open-market trading price and a reported per-share value of $0.00.

How many Trinseo (TSE) shares does Joseph Alvarado hold after the transaction?

After the reported transaction, Joseph Alvarado is shown holding 52,187 Ordinary Shares directly. This figure represents his direct ownership position following the restructuring event involving the forfeiture of restricted stock units described in the Form 4 footnote.

What exactly was forfeited in Joseph Alvarado’s Trinseo (TSE) filing?

The filing states Alvarado voluntarily forfeited restricted stock units previously granted on June 25, 2025. The footnote notes the RSU award had not vested or settled, in full or in part, when the 42,484 units associated with Ordinary Shares were forfeited.

Was the Trinseo (TSE) insider transaction a compensation-related change?

Yes. The Form 4 describes the event as an "other" transaction and the footnote links it to a voluntary forfeiture of unvested restricted stock units. This points to a compensation-related adjustment, not an open-market trade in Trinseo’s Ordinary Shares.