STOCK TITAN

[Form 4] PTC THERAPEUTICS, INC. Insider Trading Activity

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
4

Rhea-AI Filing Summary

PTC Therapeutics executive Mark Elliott Boulding reported an exercise-and-sale transaction in company stock. On May 8, 2026, he exercised stock options to acquire a total of 3,540 shares of common stock at an exercise price of $46.54 per share.

That same day, he executed open-market sales totaling 3,540 shares at prices ranging from approximately $78.00 to $79.31 per share, pursuant to a pre-arranged Rule 10b5-1 trading plan adopted on September 10, 2025. Following these transactions, he directly holds 105,212 shares of PTC Therapeutics common stock.

Positive

  • None.

Negative

  • None.
Insider Boulding Mark Elliott
Role EXEC. VP AND CLO
Sold 3,540 shs ($280K)
Type Security Shares Price Value
Exercise Stock Option (Right to Buy) 2,740 $0.00 --
Exercise Stock Option (Right to Buy) 800 $0.00 --
Exercise Common Stock 2,740 $46.54 $128K
Sale Common Stock 840 $78.23 $66K
Sale Common Stock 1,900 $79.31 $151K
Exercise Common Stock 800 $46.54 $37K
Sale Common Stock 200 $78.00 $16K
Sale Common Stock 600 $79.28 $48K
Holdings After Transaction: Stock Option (Right to Buy) — 42,260 shares (Direct, null); Common Stock — 107,952 shares (Direct, null)
Footnotes (1)
  1. This transaction was effected pursuant to a written Rule 10b5-1 plan adopted by the Reporting Person on September 10, 2025. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $78.00 to $78.72 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. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $79.03 to $79.70 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. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $79.02 to $79.52 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. This option was granted on January 3, 2025, and vests over four years, with 25% of the shares underlying the option vesting on January 3, 2026, 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 3, 2026.
Shares sold 3,540 shares Open-market sales on May 8, 2026
Sale prices $78.00–$79.31 per share Weighted average price ranges for sales
Options exercised 3,540 shares Common stock acquired via option exercise
Option exercise price $46.54 per share Exercise price for stock options
Shares held after transactions 105,212 shares Direct common stock ownership post-transaction
Transaction date May 8, 2026 Date of exercises and sales
Rule 10b5-1 plan regulatory
"This transaction was effected pursuant to a written Rule 10b5-1 plan"
A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.
weighted average price financial
"This price represents the weighted average price of sale transactions"
Weighted average price is the average price of a security where each trade or component is counted according to its size, so bigger trades pull the average more than smaller ones. Think of it like calculating the average cost of a grocery haul where items you bought more of have greater influence on the final per-item cost. Investors use it to understand the true average price paid or received, judge execution quality, and compare trading performance against market movement.
Stock Option (Right to Buy) financial
"security_title":"Stock Option (Right to Buy)"
Exercise or conversion of derivative security financial
"transaction_code_description":"Exercise or conversion of derivative security"
open-market sale financial
"transaction_action":"open-market sale"
An open-market sale is when a shareholder sells existing shares directly on a public exchange to any willing buyer, rather than through a private deal. Think of it like putting goods on a busy market stall where price is set by supply and demand; for investors it matters because such sales increase available supply, can put short-term downward pressure on the stock price, and signal changes in liquidity or investor confidence.
SEC Form 4
FORM 4UNITED 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 NEW JERSEY 07059

(City)(State)(Zip)

UNITED STATES

(Country)
2. Issuer Name and Ticker or Trading Symbol
PTC THERAPEUTICS, INC. [ PTCT ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director10% Owner
XOfficer (give title below)Other (specify below)
EXEC. VP AND CLO
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
05/08/2026
6. Individual or Joint/Group Filing (Check Applicable Line)
XForm 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)
CodeVAmount(A) or (D)Price
Common Stock05/08/2026M(1)2,740A$46.54107,952D
Common Stock05/08/2026S(1)840D$78.23(2)107,112D
Common Stock05/08/2026S(1)1,900D$79.31(3)105,212D
Common Stock05/08/2026M(1)800A$46.54106,012D
Common Stock05/08/2026S(1)200D$78105,812D
Common Stock05/08/2026S(1)600D$79.28(4)105,212D
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)
CodeV(A)(D)Date ExercisableExpiration DateTitleAmount or Number of Shares
Stock Option (Right to Buy)$46.5405/08/2026M(1)2,740 (5)01/02/2035Common Stock2,740$042,260D
Stock Option (Right to Buy)$46.5405/08/2026M(1)800 (5)01/02/2035Common Stock800$041,460D
Explanation of Responses:
1. This transaction was effected pursuant to a written Rule 10b5-1 plan adopted by the Reporting Person on September 10, 2025.
2. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $78.00 to $78.72 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 $79.03 to $79.70 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 $79.02 to $79.52 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 option was granted on January 3, 2025, and vests over four years, with 25% of the shares underlying the option vesting on January 3, 2026, 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 3, 2026.
/s/ Avraham S. Adler, Attorney-in-Fact05/12/2026
** Signature of Reporting PersonDate
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)