PTC Therapeutics insider sells shares after option exercise; 103,901 shares remain

Rhea-AI Filing Summary

Mark Elliott Boulding, Executive Vice President and CLO of PTC Therapeutics, Inc. (PTCT), reported multiple share transactions effected under a written Rule 10b5-1 plan adopted December 5, 2024. On September 11 and 12, 2025 he exercised and purchased common stock via stock options priced at $38.10 and simultaneously sold portions of his holdings in a series of transactions with weighted average sale prices ranging from $61.00 to $62.18 per share. Following the reported trades, the filing shows beneficial ownership of 103,901 common shares. The form also discloses outstanding stock options exercisable into specific share amounts with an expiration date of January 6, 2032 and vesting tied to a grant from January 7, 2022.

Positive

• Transactions executed under a written Rule 10b5-1 plan (adopted Dec 5, 2024), indicating pre-planned trading
• Exercise of stock options at $38.10 and disclosure of long-dated option expirations (01/06/2032), maintaining potential future upside
• Detailed price disclosure including weighted-average prices and willingness to provide trade-level information on request

Negative

• Significant sales reduced beneficial ownership to 103,901 common shares following transactions on Sept 11–12, 2025
• Multiple sales at prices between $61.00 and $62.18 indicate realization of gains and a lower post-trade share count

Insights

Securities Analyst

TL;DR: Insider followed a pre-established 10b5-1 plan to exercise options at $38.10 and sell shares at ~$61–$62, ending with 103,901 shares beneficially owned.

The transactions are executed under a written Rule 10b5-1 plan, indicating they were pre-planned rather than opportunistic trading. Several option exercises increased direct holdings before weighted-average sales reduced reported beneficial ownership to 103,901 shares. The presence of long-dated options (expiring 01/06/2032) preserves future upside for the insider while the sales crystallized gains given the exercise price of $38.10 compared with sale prices near $61–$62.

Corporate Governance Expert

TL;DR: Use of a documented 10b5-1 plan and attorney-in-fact signature suggests procedural compliance and pre-planned disposition of shares.

The filing shows formal compliance elements: a disclosed 10b5-1 plan adoption date and an attorney-in-fact signature. The option grant and vesting schedule from January 7, 2022 are clearly noted, and the reporting person committed to provide trade-level price details upon request. These disclosures meet typical transparency expectations for insider transactions.

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).

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)
09/11/2025

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	09/11/2025		M(1)		17,838	A	$38.1	121,739	D
Common Stock	09/11/2025		S(1)		17,838	D	$61(2)	103,901	D
Common Stock	09/11/2025		M(1)		2,356	A	$38.1	106,257	D
Common Stock	09/11/2025		S(1)		2,356	D	$61(3)	103,901	D
Common Stock	09/11/2025		M(1)		2,470	A	$38.1	106,371	D
Common Stock	09/11/2025		S(1)		2,470	D	$61(4)	103,901	D
Common Stock	09/12/2025		M(1)		22,661	A	$38.1	126,562	D
Common Stock	09/12/2025		S(1)		22,117	D	$61.33(5)	104,445	D
Common Stock	09/12/2025		S(1)		544	D	$62.09(6)	103,901	D
Common Stock	09/12/2025		M(1)		1,019	A	$38.1	104,920	D
Common Stock	09/12/2025		S(1)		1,019	D	$61.31(7)	103,901	D
Common Stock	09/12/2025		M(1)		905	A	$38.1	104,806	D
Common Stock	09/12/2025		S(1)		905	D	$61.21(8)	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)	$38.1	09/11/2025		M(1)			17,838	(9)	01/06/2032	Common Stock	17,838	$0	36,162	D
Stock Option (Right to Buy)	$38.1	09/11/2025		M(1)			2,356	(9)	01/06/2032	Common Stock	2,356	$0	33,806	D
Stock Option (Right to Buy)	$38.1	09/11/2025		M(1)			2,470	(9)	01/06/2032	Common Stock	2,470	$0	31,336	D
Stock Option (Right to Buy)	$38.1	09/12/2025		M(1)			22,661	(9)	01/06/2032	Common Stock	22,661	$0	8,675	D
Stock Option (Right to Buy)	$38.1	09/12/2025		M(1)			1,019	(9)	01/06/2032	Common Stock	1,019	$0	7,656	D
Stock Option (Right to Buy)	$38.1	09/12/2025		M(1)			905	(9)	01/06/2032	Common Stock	905	$0	6,751	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 $61.00 to $61.08 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 price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $61.00 to $61.02 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.

4. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $61.00 to $61.04 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.

5. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $61.00 to $61.99 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.

6. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $62.05 to $62.18 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.

7. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $61.00 to $61.83 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.

8. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $61.00 to $61.86 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.

9. This option was granted on January 7, 2022, and vests over four years, with 25% of the shares underlying the option vesting on January 7, 2023, 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 April 7, 2023.

	/s/ Avraham S. Adler, Attorney-in-Fact	09/15/2025
	** 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

Who filed this Form 4 for PTCT?

The filing was made by Mark Elliott Boulding, Executive Vice President and CLO of PTC Therapeutics, Inc.

Were the trades part of a pre-planned trading program?

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

What prices were shares sold and options exercised at?

Options were exercised at $38.10. Sales had weighted-average prices ranging from $61.00 to $62.18 per share depending on the trade.

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

The filing reports beneficial ownership of 103,901 common shares following the reported transactions.

What is the expiration and vesting information for the stock options?

The options underlying the reported exercises expire on January 6, 2032 and were granted on January 7, 2022 with a specified vesting schedule.

Is there additional trade-level pricing detail available?

Yes. The reporting person states they will provide full information regarding the number of shares sold at each separate price upon request by the SEC staff, the issuer, or a security holder.