STOCK TITAN

PTC Therapeutics (NASDAQ: PTCT) CLO sells 2,813 shares under 10b5-1 plan

(Neutral)
(Neutral)
Form Type
4

Rhea-AI Filing Summary

PTC THERAPEUTICS, INC. (PTCT) executive vice president and CLO Mark Elliott Boulding exercised stock options for 2,813 shares of common stock at an exercise price of $25.69 per share and then sold those 2,813 shares in two tranches at weighted average prices of $72.39 and $72.90 on August 17, 2026. Following the option exercise, he held 16,876 stock options under that award, which was granted on February 15, 2024 and vests over four years. These transactions were effected pursuant to a written Rule 10b5-1 plan adopted on September 10, 2025.

Positive

  • None.

Negative

  • None.
Insider Boulding Mark Elliott
Role EXEC. VP AND CLO
Sold 2,813 shs ($204K)
Approx. gross sale proceeds $204K
Approx. exercise cost $72K
Approx. pre-tax spread $132K
Type Security Shares Price Value
Exercise Stock Option (Right to Buy) F1, F4 2,813 $0.00 $0.00
Exercise Common Stock F1 2,813 $25.69 $72K
Sale Common Stock F1, F2 1,844 $72.39 $133K
Sale Common Stock F1, F3 969 $72.90 $71K
Holdings After Transaction: Stock Option (Right to Buy) — 16,876 shares (Direct); Common Stock — 105,272 shares (Direct)
Footnotes (4)
  1. F1. This transaction was effected pursuant to a written Rule 10b5-1 plan adopted by the Reporting Person on September 10, 2025.
  2. F2. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $71.72 to $72.67 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. F3. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $72.73 to $73.02 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. F4. This option was granted on February 15, 2024, and vests over four years, with 25% of the shares underlying the option vesting 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.
Options exercised 2,813 shares Stock options exercised into PTCT common stock on 2026-08-17
Option exercise price $25.69 per share Exercise price of stock option converted into 2,813 PTCT shares
Shares sold at $72.39 1,844 shares Weighted average sale price of $72.39 on 2026-08-17
Shares sold at $72.90 969 shares Weighted average sale price of $72.90 on 2026-08-17
Options remaining 16,876 options Stock options beneficially owned after the reported option exercise
Rule 10b5-1 plan adoption date 2025-09-10 Date the written Rule 10b5-1 trading plan was adopted
Option expiration date 2034-02-14 Expiration date of the stock option that was partially exercised
Rule 10b5-1 plan regulatory
"This transaction was effected pursuant to a written Rule 10b5-1 plan adopted"
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.
Stock Option (Right to Buy) financial
"security_title": "Stock Option (Right to Buy)""
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.
vests over four years financial
"This option was granted on February 15, 2024, and vests over four years"
A grant that "vests over four years" is a promise that ownership of awarded company shares or options becomes permanent in small portions over a four-year period instead of all at once. Think of it like earning a four-year subscription one month at a time: the recipient gains the right to a bit more stock as time passes, which matters to investors because it affects when employees can sell shares, how quickly ownership shifts, and the timing of potential dilution or insider selling.

FAQ

What insider transaction did PTCT executive Mark Elliott Boulding report on this Form 4?

Mark Elliott Boulding exercised 2,813 stock options and acquired an equal number of PTCT common shares, then sold all 2,813 shares in two transactions on August 17, 2026. The filing also reports 16,876 options remaining from that grant after the exercise.

At what prices did the PTCT insider sell common stock on August 17, 2026?

He sold PTCT common stock at weighted average prices of $72.39 for 1,844 shares and $72.90 for 969 shares. Footnotes state these averages reflect multiple trades within price ranges of $71.72–$72.67 and $72.73–$73.02, respectively.

What was the stock option exercise price reported by the PTCT insider?

The exercised PTCT stock options had an exercise price of $25.69 per share for 2,813 underlying shares. The option was granted on February 15, 2024, vests over four years, and expires on February 14, 2034, according to the footnote disclosure.

How many PTCT stock options does Mark Elliott Boulding hold after the reported transactions?

After exercising options for 2,813 shares, he held 16,876 stock options from the same grant. This figure represents options remaining following the August 17, 2026 exercise and is reported as the total derivative securities beneficially owned after the transaction.

Were the August 17, 2026 PTCT insider transactions under a Rule 10b5-1 plan?

Yes. A footnote states all reported transactions were effected under a written Rule 10b5-1 plan adopted on September 10, 2025. Such plans pre-arrange trading activity, which can reduce the informational value of the exact timing of the reported sales.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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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)
08/17/2026
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 Stock08/17/2026M(1)2,813A$25.69108,085D
Common Stock08/17/2026S(1)1,844D$72.39(2)106,241D
Common Stock08/17/2026S(1)969D$72.9(3)105,272D
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)$25.6908/17/2026M(1)2,813 (4)02/14/2034Common Stock2,813$016,876D
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 $71.72 to $72.67 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 $72.73 to $73.02 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 option was granted on February 15, 2024, and vests over four years, with 25% of the shares underlying the option vesting 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-Fact08/19/2026
** 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)