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PTC Therapeutics (NASDAQ: PTCT) director sells 25,000 shares in 10b5-1 trade

Filing Impact
(High)
Filing Sentiment
(Negative)
Form Type
4

Rhea-AI Filing Summary

PTC THERAPEUTICS, INC. (PTCT) director Michael Schmertzler reported indirect sales of an aggregate 25,000 shares of common stock on August 19–20, 2026. The sales were made by Section Six Partners, L.P., where he is a general and limited partner, pursuant to a written Rule 10b5-1 plan adopted on May 14, 2026. The reported weighted average prices ranged from the low $70s to the mid $73s per share across multiple trade buckets. Schmertzler reports separate direct ownership of 163,266 shares of PTCT common stock and disclaims beneficial ownership of the partnership-held shares except to the extent of his pecuniary interest.

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Insider SCHMERTZLER MICHAEL
Role Director
Sold 25,000 shs ($1.81M)
Type Security Shares Price Value
Sale Common Stock F1, F5, F3 9,419 $70.78 $667K
Sale Common Stock F1, F6, F3 2,390 $71.88 $172K
Sale Common Stock F1, F7, F3 691 $72.92 $50K
Sale Common Stock F1, F2, F3 5,335 $72.86 $389K
Sale Common Stock F1, F4, F3 7,165 $73.67 $528K
holding Common Stock -- -- --
Holdings After Transaction: Common Stock — 1,361,594 shares (Indirect, See footnote); Common Stock — 163,266 shares (Direct)
Footnotes (7)
  1. F1. This transaction was effected pursuant to a written Rule 10b5-1 plan adopted by Section Six Partners, L.P., of which the Reporting Person is a general partner and limited partner, on May 14, 2026
  2. F2. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $72.33 to $73.32 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. Represents shares of common stock held by Section Six Partners, L.P. The Reporting Person is a general and limited partner of Section Six Partners, L.P. The Reporting Person disclaims beneficial ownership of the shares of common stock held by Section Six Partners, L.P. except to the extent of his pecuniary interest therein.
  4. F4. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $73.33 to $74.02 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.
  5. F5. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $70.50 to $71.49 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. F6. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $71.50 to $72.46 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. F7. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $72.60 to $73.48 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.
Total shares sold 25,000 shares Aggregate indirect sales of PTCT common stock reported for August 19–20, 2026
Weighted average sale price (Aug 19, 2026 block) $72.86 per share 5,335-share indirect sale with trades from $72.33 to $73.32 per share
Weighted average sale price (Aug 19, 2026 block) $73.67 per share 7,165-share indirect sale with trades from $73.33 to $74.02 per share
Weighted average sale price (Aug 20, 2026 block) $70.78 per share 9,419-share indirect sale with trades from $70.50 to $71.49 per share
Weighted average sale price (Aug 20, 2026 block) $71.88 per share 2,390-share indirect sale with trades from $71.50 to $72.46 per share
Weighted average sale price (Aug 20, 2026 block) $72.92 per share 691-share indirect sale with trades from $72.60 to $73.48 per share
Direct holdings after transactions 163,266 shares Directly held PTCT common stock reported as of August 19, 2026
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.
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.
beneficial ownership regulatory
"The Reporting Person disclaims beneficial ownership of the shares of common stock"
Beneficial ownership means the person or entity that actually enjoys the benefits of owning shares or other assets — such as receiving dividends, voting rights, or price gains — even if the legal title is held in another name. For investors it matters because knowing who truly controls and profits from a company reveals who can influence decisions, exposes potential conflicts of interest or hidden concentration of power, and affects transparency and risk in the stock.
pecuniary interest financial
"except to the extent of his pecuniary interest therein"

FAQ

Who is the insider in PTCT’s latest Form 4 and what is his role?
The insider is Michael Schmertzler, who is reported as a director of PTC THERAPEUTICS, INC. (PTCT). He filed a Form 4 describing indirect sales of the company’s common stock through an affiliated limited partnership.

How many PTCT shares were sold in this Form 4 by Michael Schmertzler’s affiliated entity?
The filing reports aggregate indirect sales of 25,000 shares of PTCT common stock on August 19–20, 2026, executed in multiple trade buckets at different weighted average prices within the low-$70 per share range.

At what prices were the PTCT shares sold in Michael Schmertzler’s Form 4?
Weighted average sale prices were reported as $72.86 and $73.67 on August 19, 2026, and $70.78, $71.88, and $72.92 on August 20, 2026, with underlying individual trades occurring in ranges from $70.50 to $74.02 per share.

Were the PTCT share sales by Michael Schmertzler under a Rule 10b5-1 trading plan?
Yes. A footnote states the transactions were effected pursuant to a written Rule 10b5-1 plan adopted by Section Six Partners, L.P. on May 14, 2026, and the Form 4’s Rule 10b5-1 checkbox is marked as affirmative.

How are the sold PTCT shares held in Michael Schmertzler’s Form 4?
The 25,000 shares sold are reported as held indirectly by Section Six Partners, L.P.. Schmertzler is a general and limited partner there and disclaims beneficial ownership of those shares except to the extent of his pecuniary interest.

How many PTCT shares does Michael Schmertzler report owning directly after these transactions?
The Form 4 includes a direct-holdings entry showing 163,266 shares of PTCT common stock held directly by Michael Schmertzler as of August 19, 2026. This figure is reported separately from the partnership-held shares that were sold.

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Form 4 Insider Transactions: What Each Field Means →
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*
SCHMERTZLER MICHAEL
(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)
XDirector10% Owner
Officer (give title below)Other (specify below)
2a. Foreign Trading Symbol
3. Date of Earliest Transaction (Month/Day/Year)
08/19/2026		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 Stock163,266D
Common Stock08/19/2026S(1)5,335D$72.86(2)1,381,259ISee footnote(3)
Common Stock08/19/2026S(1)7,165D$73.67(4)1,374,094ISee footnote(3)
Common Stock08/20/2026S(1)9,419D$70.78(5)1,364,675ISee footnote(3)
Common Stock08/20/2026S(1)2,390D$71.88(6)1,362,285ISee footnote(3)
Common Stock08/20/2026S(1)691D$72.92(7)1,361,594ISee footnote(3)
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
Explanation of Responses:
1. This transaction was effected pursuant to a written Rule 10b5-1 plan adopted by Section Six Partners, L.P., of which the Reporting Person is a general partner and limited partner, on May 14, 2026
2. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $72.33 to $73.32 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. Represents shares of common stock held by Section Six Partners, L.P. The Reporting Person is a general and limited partner of Section Six Partners, L.P. The Reporting Person disclaims beneficial ownership of the shares of common stock held by Section Six Partners, L.P. except to the extent of his pecuniary interest therein.
4. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $73.33 to $74.02 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.
5. This price represents the weighted average price of sale transactions that were executed in multiple trades at prices ranging from $70.50 to $71.49 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 $71.50 to $72.46 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 $72.60 to $73.48 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.
/s/ Avraham S. Adler, Attorney-in-Fact08/21/2026
** 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)

Source: View Original Filing on SEC EDGAR