PTC Therapeutics director sells 20,000 shares

PTC THERAPEUTICS, INC.

Rhea-AI Filing Summary

PTC THERAPEUTICS, INC. (PTCT) reported that director Michael Schmertzler, through Section Six Partners, L.P., filed a Form 4 for indirect sales of a total of 20,000 shares of common stock on September 9–10, 2026 under a written Rule 10b5-1 trading plan adopted on May 14, 2026.

The shares are held by Section Six Partners, L.P., where Schmertzler is a general and limited partner, and he disclaims beneficial ownership of those shares except to the extent of his pecuniary interest.

Insider Trade Summary 10b5-1

Net Seller: 20,000 shares

Net Sell 3 txns

Insider SCHMERTZLER MICHAEL

Role Director

Sold 20,000 shs ($1.35M)

Type	Security	Shares	Price	Value
Sale	Common Stock F1, F5, F3	10,000	$67.34	$673K
Sale	Common Stock F1, F2, F3	9,428	$67.79	$639K
Sale	Common Stock F1, F4, F3	572	$68.67	$39K

Holdings After Transaction: Common Stock — 1,316,594 shares (Indirect, See footnote)

Footnotes (5)

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 $67.54 to $68.52 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.
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 $68.54 to $68.76 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 $66.84 to $67.66 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.

Key Figures

Shares sold September 10, 2026: 10,000 shares Shares sold September 9, 2026 (block 1): 9,428 shares Shares sold September 9, 2026 (block 2): 572 shares +2 more

5 metrics

Shares sold September 10, 2026 10,000 shares Indirect sale of common stock at a weighted average price of $67.34 per share

Shares sold September 9, 2026 (block 1) 9,428 shares Indirect sale of common stock at a weighted average price of $67.79 per share

Shares sold September 9, 2026 (block 2) 572 shares Indirect sale of common stock at a weighted average price of $68.67 per share

Total shares sold 20,000 shares Aggregate of three indirect sales reported in this Form 4

Rule 10b5-1 plan adoption date May 14, 2026 Date Section Six Partners, L.P. adopted the written trading plan used for these sales

Key Terms

Rule 10b5-1 plan, weighted average price, pecuniary interest, disclaims beneficial ownership, +1 more

5 terms

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.

pecuniary interest financial

"except to the extent of his pecuniary interest therein"

disclaims beneficial ownership regulatory

"The Reporting Person disclaims beneficial ownership of the shares"

Section Six Partners, L.P. financial

"Represents shares of common stock held by Section Six Partners, L.P."

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

How many PTCT shares were sold in this Form 4 by director Michael Schmertzler?

The filing reports indirect sales totaling 20,000 shares of PTC Therapeutics common stock, executed in three transactions on September 9–10, 2026 through Section Six Partners, L.P.

On what dates and at what prices were PTCT shares sold in this Form 4?

Sales occurred on September 9, 2026 (9,428 shares at a weighted average of $67.79 and 572 shares at $68.67) and on September 10, 2026 (10,000 shares at $67.34), each representing weighted average prices over specified intraday ranges.

Were the PTCT stock sales made under a Rule 10b5-1 plan?

Yes. The transactions were effected pursuant to a written Rule 10b5-1 plan adopted by Section Six Partners, L.P. on May 14, 2026, as indicated by both the plan checkbox and the footnote description.

Who actually holds the PTCT shares involved in this Form 4?

The reported shares are held by Section Six Partners, L.P. The reporting person, Michael Schmertzler, is a general and limited partner of that partnership, and the filing states he disclaims beneficial ownership except to the extent of his pecuniary interest.

What is Michael Schmertzler’s relationship to PTC Therapeutics (PTCT)?

The filing identifies Michael Schmertzler as a director of PTC Therapeutics, Inc. He is reporting indirect transactions in the company’s common stock through Section Six Partners, L.P.

How are the PTCT sale prices in this Form 4 calculated?

For each transaction, the reported price is a weighted average sale price. Footnotes explain that the sales were executed in multiple trades within specified ranges, such as $67.54–$68.52, and the reporting person undertakes to provide detailed trade breakdowns upon request.

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

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Available on EDGAR 09/11/2026 - 05:20 PM Accepted by SEC EDGAR 09/11/2026 - 05:20 PM Learn about SEC filing dates

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).

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)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/09/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form 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)
			Code	V	Amount	(A) or (D)	Price
Common Stock	09/09/2026		S(1)		9,428	D	$67.79(2)	1,327,166	I	See footnote(3)
Common Stock	09/09/2026		S(1)		572	D	$68.67(4)	1,326,594	I	See footnote(3)
Common Stock	09/10/2026		S(1)		10,000	D	$67.34(5)	1,316,594	I	See 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)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount 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 $67.54 to $68.52 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.

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 $68.54 to $68.76 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 $66.84 to $67.66 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-Fact	09/11/2026
	** 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.
* Form 4: SEC 1474 (03-26)