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

Rhea-AI Filing Summary

PTC Therapeutics insider transactions on 08/15/2025 show Executive Vice President and CLO Mark Elliott Boulding exercised options to buy 2,813 shares at an exercise price of $25.69 and simultaneously sold 2,813 shares at a weighted average sale price of $48.58 per share under a Rule 10b5-1 plan. After the transactions, Mr. Boulding beneficially owned 103,901 shares of common stock and held 24,899 shares subject to unexercised options. The option was originally granted on February 14, 2024, vests over four years with an initial 25% vesting on February 15, 2025 and subsequent 6.25% quarterly vesting starting May 15, 2025. The Rule 10b5-1 plan was adopted December 5, 2024. The sale prices executed ranged from $48.24 to $49.11 and the filer offers to provide per-trade quantities upon request.

Positive

• Full disclosure of exercise price, sale weighted average price, sale price range, and post-transaction ownership
• Transaction executed under a Rule 10b5-1 plan adopted on December 5, 2024, supporting an affirmative defense
• Relatively small transaction size (2,813 shares) which is unlikely to be material to company valuation

Negative

• No indication of per-trade quantities in the filing for sales at each price point; reporter offers to provide on request
• Filer remains an executive officer so continued insider holdings could be viewed as a potential conflict by some investors

Insights

Securities Analyst

TL;DR Insider exercised options at $25.69 and sold the same shares at a weighted average $48.58 under a pre-established 10b5-1 plan.

The transaction is a routine, non-discretionary monetization of option gains by a senior executive rather than a discretionary open-market sale. The exercise-to-sale sequence is fully described with exact quantities and prices and was executed pursuant to a Rule 10b5-1 plan adopted December 5, 2024, which supports an affirmative defense against insider trading claims. The weighted average sale price and disclosed price range permit precise calculation of proceeds without additional assumptions. From a market-impact perspective, the size of the trades (2,813 shares) is small relative to typical public-company float and therefore unlikely to be material to the company valuation.

Corporate Governance Expert

TL;DR The filing documents compliant execution of an option exercise and concurrent sale under a 10b5-1 plan, with full explanatory disclosure.

The reporting includes required details: plan adoption date, option grant and vesting schedule, exercise price, sale price range, and an undertaking to provide per-trade quantities on request. This level of disclosure aligns with good governance practices for officers monetizing equity. No indication of accelerated vesting or exceptions is present. The post-transaction beneficial ownership figures are clearly stated, supporting transparency for investors and regulators.

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^*

Boulding Mark Elliott

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EXEC. VP AND CLO

3. Date of Earliest Transaction (Month/Day/Year)
08/15/2025

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	08/15/2025		M(1)		2,813	A	$25.69	106,714	D
Common Stock	08/15/2025		S(1)		2,813	D	$48.58(2)	103,901	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)	$25.69	08/15/2025		M(1)			2,813	(3)	02/14/2034	Common Stock	2,813	$0	24,899	D

Explanation of Responses:

1. This transaction was effected pursuant to a written Rule 10b5-1 plan adopted by the Reporting Person on December 5, 2024.

2. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $48.24 to $49.11 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.

3. This option was granted on February 14, 2024 and vests over four years, with 25% of the shares underlying the option vested on February 15, 2025, and an additional 6.25% of the original number of shares underlying the option vesting at the end of each successive three-month period thereafter, beginning on May 15, 2025.

	/s/ Avraham S. Adler, Attorney-in-Fact	08/19/2025
	** 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 did PTCT insider Mark Elliott Boulding do on 08/15/2025?

He exercised 2,813 options at $25.69 and sold 2,813 shares at a weighted average price of $48.58 under a Rule 10b5-1 plan.

Was the sale part of a Rule 10b5-1 plan for PTCT insider transactions?

Yes. The filing states the transactions were effected pursuant to a Rule 10b5-1 plan adopted on December 5, 2024.

How many PTCT shares does the reporting person own after these transactions?

Following the reported transactions he beneficially owned 103,901 shares and held 24,899 shares subject to unexercised options.

What was the sale price range for the PTCT shares sold?

Sales were executed at prices ranging from $48.24 to $49.11 per share; the weighted average sale price reported is $48.58.

When was the underlying option granted and what is the vesting schedule?

The option was granted on February 14, 2024 with 25% vested on February 15, 2025 and additional 6.25% of the original grant vesting each quarter beginning May 15, 2025.