Tax-related share sale by PTC Therapeutics (PTCT) CEO Matthew B. Klein

Rhea-AI Filing Summary

PTC Therapeutics, Inc. reported an insider share sale by its chief executive officer Matthew B. Klein. On January 8, 2026, he sold 2,514 shares of common stock at $76.45 per share. After this transaction, he beneficially owned 394,453 shares of PTC Therapeutics common stock in direct ownership.

The filing explains that these shares were automatically sold under an irrevocable “sell to cover” election to satisfy tax withholding obligations tied to the vesting of 5,250 restricted stock units (RSUs) from a January 7, 2022 grant of 21,000 RSUs. This indicates the sale was made to cover taxes due on equity compensation rather than as a discretionary open‑market sale of investment holdings.

Insider Trade Summary

Net Seller: 2,514 shares ($192,195)

Net Sell 1 txn

Insider Klein Matthew B.

Role CHIEF EXECUTIVE OFFICER

Sold 2,514 shs ($192K)

Type	Security	Shares	Price	Value
Sale	Common Stock	2,514	$76.45	$192K

Holdings After Transaction: Common Stock — 394,453 shares (Direct)

Footnotes (1)

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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).

X

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^*

Klein Matthew B.

(Last) (First) (Middle)

C/O PTC THERAPEUTICS, INC.

500 WARREN CORPORATE CENTER DRIVE

(Street)

WARREN NJ 07059

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
PTC THERAPEUTICS, INC. [ PTCT ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	CHIEF EXECUTIVE OFFICER

3. Date of Earliest Transaction (Month/Day/Year)
01/08/2026

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
Common Stock	01/08/2026		S		2,514(1)	D	$76.45	394,453	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 shares automatically sold pursuant to irrevocable sell to cover elections entered into upon acceptance of the respective grants to satisfy tax withholding obligations in connection with the vesting of 5,250 RSUs from a January 7, 2022 grant of 21,000 RSUs.

	/s/ Avraham S. Adler, Attorney-in-Fact	01/12/2026
	** 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.

FAQ

Who reported the insider transaction in PTC Therapeutics (PTCT)?

The transaction was reported by Matthew B. Klein, who serves as both a director and the Chief Executive Officer of PTC Therapeutics, Inc..

How many PTC Therapeutics (PTCT) shares did the CEO sell and at what price?

On January 8, 2026, the CEO sold 2,514 shares of common stock of PTC Therapeutics at a price of $76.45 per share.

Why were the PTC Therapeutics (PTCT) shares sold in this Form 4 filing?

According to the explanation, the shares were automatically sold under irrevocable sell to cover elections to satisfy tax withholding obligations arising from the vesting of 5,250 RSUs from a January 7, 2022 grant of 21,000 RSUs.

How many PTC Therapeutics (PTCT) shares does the CEO own after this transaction?

Following the reported transaction, the CEO beneficially owned 394,453 shares of PTC Therapeutics common stock in direct ownership.

Is the PTC Therapeutics (PTCT) CEO a 10% owner based on this Form 4?

In the filing, the box for 10% Owner is not checked, while the boxes for Director and Officer (Chief Executive Officer) are checked, indicating he is not reported as a 10% owner here.

Does this PTC Therapeutics (PTCT) Form 4 involve derivative securities or only common stock?

The reported transaction in Table I involves common stock. Table II for derivative securities is present but does not list any specific derivative transactions in this excerpt.