STOCK TITAN

PTC Therapeutics (PTCT) CLO sells shares under Rule 10b5-1 plan

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

Rhea-AI Filing Summary

PTC Therapeutics executive Mark Elliott Boulding reported both sales and option exercises in PTC THERAPEUTICS, INC. common stock. On July 6, 2026, he sold 5,079 shares in a series of open‑market transactions at weighted average prices spanning $82.76 to $86.73. These sales were executed under a written Rule 10b5‑1 trading plan adopted on September 10, 2025.

On the same date, he exercised stock options to acquire 5,039 shares at strike prices of $46.54 and $39.42. Following the transactions, Boulding directly owns 105,272 shares of PTC Therapeutics common stock, and the filing shows remaining stock options outstanding in multiple series.

Positive

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Negative

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Insider Boulding Mark Elliott
Role EXEC. VP AND CLO
Sold 5,079 shs ($432K)
Type Security Shares Price Value
Exercise Stock Option (Right to Buy) 2,226 $0.00 --
Exercise Stock Option (Right to Buy) 2,813 $0.00 --
Exercise Common Stock 2,266 $39.42 $89K
Sale Common Stock 313 $83.10 $26K
Sale Common Stock 833 $84.41 $70K
Sale Common Stock 519 $85.84 $45K
Sale Common Stock 601 $86.38 $52K
Exercise Common Stock 2,813 $46.54 $131K
Sale Common Stock 387 $83.10 $32K
Sale Common Stock 1,036 $84.41 $87K
Sale Common Stock 645 $85.84 $55K
Sale Common Stock 745 $86.38 $64K
Holdings After Transaction: Stock Option (Right to Buy) — 4,532 shares (Direct, null); Common Stock — 107,538 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 $82.76 to $83.68 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 $83.98 to $84.94 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 $85.18 to $86.17 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 $86.18 to $86.73 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 5, 2023 and vests over four years, with 25% of the shares underlying the option vesting on January 5, 2024, 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 5, 2024. 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 5,079 shares Common Stock open-market sales on July 6, 2026
Shares acquired via option exercise 5,039 shares Common Stock from option exercises on July 6, 2026
Post-transaction common shares held 105,272 shares Direct ownership after July 6, 2026 transactions
Sale price range $82.76–$86.73 per share Weighted average sale price bands for multiple trades
Option strike price 1 $46.54 per share Stock option (Right to Buy) exercised into 2,813 shares
Option strike price 2 $39.42 per share Stock option (Right to Buy) exercised into 2,266 shares
Remaining options at $46.54 28,125 options Stock options outstanding, expiring January 2, 2035
Remaining options at $39.42 4,532 options Stock options outstanding, expiring January 4, 2033
Rule 10b5-1 plan financial
"This transaction was effected pursuant to a written Rule 10b5-1 plan adopted by the Reporting Person"
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 that were executed in multiple trades"
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)"
vests over four years financial
"This option was granted on January 5, 2023 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.
derivative exercise/conversion financial
"transaction_action: derivative exercise/conversion"
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FAQ

What insider transactions did PTCT executive Mark Elliott Boulding report?

Mark Elliott Boulding reported both sales and option exercises in PTC Therapeutics common stock. He sold 5,079 shares in open‑market transactions and exercised stock options to acquire 5,039 shares, all dated July 6, 2026, according to the Form 4 data.

How many PTC Therapeutics (PTCT) shares did Boulding sell and at what prices?

Boulding sold 5,079 PTCT common shares in multiple open‑market trades. The weighted average prices for these sales ranged from $82.76 to $86.73 per share, reflecting several price bands disclosed through detailed footnotes in the Form 4 filing.

Were Mark Elliott Boulding’s PTCT stock sales made under a Rule 10b5-1 plan?

Yes. The Form 4 footnotes state the transactions were effected under a written Rule 10b5‑1 trading plan. This plan was adopted on September 10, 2025, indicating the July 6, 2026 sales were pre‑arranged rather than timed on a discretionary, same‑day basis.

How many PTC Therapeutics (PTCT) shares does Boulding hold after these transactions?

After the reported transactions, Boulding directly owns 105,272 shares of PTC Therapeutics common stock. This post‑transaction balance appears in the non‑derivative transaction table, providing context for the scale of his reported sales and option exercises on July 6, 2026.

What stock options in PTCT did Boulding exercise, and what are their strike prices?

Boulding exercised options covering 5,039 underlying PTCT shares. These options had exercise prices of $46.54 and $39.42 per share. Footnotes explain the options were originally granted in 2023 and 2025 and vest over four years in scheduled quarterly installments.
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)
07/06/2026
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 Stock07/06/2026M(1)2,266A$39.42107,538D
Common Stock07/06/2026S(1)313D$83.1(2)107,225D
Common Stock07/06/2026S(1)833D$84.41(3)106,392D
Common Stock07/06/2026S(1)519D$85.84(4)105,873D
Common Stock07/06/2026S(1)601D$86.38(5)105,272D
Common Stock07/06/2026M(1)2,813A$46.54108,085D
Common Stock07/06/2026S(1)387D$83.1(2)107,698D
Common Stock07/06/2026S(1)1,036D$84.41(3)106,662D
Common Stock07/06/2026S(1)645D$85.84(4)106,017D
Common Stock07/06/2026S(1)745D$86.38(5)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)$39.4207/06/2026M(1)2,226 (6)01/04/2033Common Stock2,266$04,532D
Stock Option (Right to Buy)$46.5407/06/2026M(1)2,813 (7)01/02/2035Common Stock2,813$028,125D
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 $82.76 to $83.68 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 $83.98 to $84.94 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 $85.18 to $86.17 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 $86.18 to $86.73 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 option was granted on January 5, 2023 and vests over four years, with 25% of the shares underlying the option vesting on January 5, 2024, 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 5, 2024.
7. 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-Fact07/08/2026
** 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)