[Form 4] PTC Therapeutics, Inc. Insider Trading Activity

Rhea-AI Filing Summary

PTC Therapeutics director David P. Southwell reported option exercise and concurrent sale on 09/09/2025. He exercised 12,000 stock options16,850 shares beneficially owned following the transactions and that the exercised options were currently exercisable. The reporting was made by attorney-in-fact Avraham S. Adler on 09/11/2025. The seller undertakes to provide trade-level details on request to the SEC.

Positive

• Clear transparency: The filing discloses exercise and sale with a commitment to provide per-trade pricing if requested.
• Realized premium: Shares sold at a weighted average of $58.34 versus exercise price $30.86, indicating a substantial pre-tax gain on exercised options.
• Options were vested: The derivative item is noted as currently exercisable, showing the director had vested rights to exercise.

Negative

• Reduction in direct ownership: The director's beneficial holdings decreased to 16,850 shares after the sale.
• Potential signaling risk: While routine, insider sales can be interpreted variably by market participants depending on context.

Insights

Securities Analyst

TL;DR: Routine director exercise and sale of vested options, monetizing equity at a substantial premium to exercise price.

The transaction shows a director exercised 12,000 options at $30.86 and sold exactly 12,000 shares at a weighted average of $58.34, indicating a realized spread of roughly $27.48 per share before taxes and fees. The exercise was noted as currently exercisable, consistent with vested options. For investors, this is a commonplace liquidity event by an insider and does not, by itself, signal material change in company fundamentals.

Corporate Governance Expert

TL;DR: Insider followed standard disclosure for a planned exercise-and-sale; documentation commitments are in place.

The Form 4 discloses both the option exercise (code M) and the sale (code S) on the same date, suggesting a simultaneous exercise-and-sell execution. The filer includes the SEC-available commitment to provide per-trade sale prices, which preserves transparency. This filing reflects routine director liquidity management rather than a governance or compliance concern.

09/11/2025 - 04:30 PM

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^*

SOUTHWELL DAVID P

(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
	Officer (give title below)		Other (specify below)

3. Date of Earliest Transaction (Month/Day/Year)
09/09/2025

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
Common Stock	09/09/2025		M		12,000	A	$30.86	28,850	D
Common Stock	09/09/2025		S		12,000	D	$58.34(1)	16,850	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
Stock Option (Right to Buy)	$30.86	09/09/2025		M			12,000	(2)	01/03/2026	Common Stock	12,000	$0	0	D

Explanation of Responses:

1. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $58.31 to $58.45 per share. The Reporting Person hereby undertakes, upon request by the SEC staff, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price.

2. Currently exercisable.

	/s/ Avraham S. Adler, Attorney-in-Fact	09/11/2025
	** 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 transactions did David P. Southwell report on Form 4 for PTCT?

He exercised 12,000 stock options at $30.86 per share and sold 12,000 shares at a weighted average price of $58.34 on 09/09/2025.

How many shares does the reporting person beneficially own after the transactions?

16,850 shares beneficially owned following the reported transactions.

Were the options exercised by the reporting person vested and exercisable?

Yes. The filing states the options were "currently exercisable."

Who signed or filed the Form 4 on behalf of the reporting person?

The Form 4 was signed by Avraham S. Adler, Attorney-in-Fact, on 09/11/2025.

What was the weighted average sale price and price range disclosed?

The weighted average sale price was $58.34, with executed trade prices ranging from $58.31 to $58.45 per the filing.