A Form 4 filed with the SEC on September 18, 2026 discloses that Michael Schmertzler, a director of PTC Therapeutics, Inc. (NASDAQ:PTCT), sold a total of 20,000 shares of common stock on September 16 and 17, 2026, through Section Six Partners, L.P., pursuant to a pre-established Rule 10b5-1 trading plan.

Key Highlights

  • Reporting person: Michael Schmertzler, identified as a director of PTC Therapeutics, Inc.
  • Shares sold on September 16, 2026: 2,994 shares at a weighted average price of $66.58, and 7,006 shares at a weighted average price of $67.35, for a combined 10,000 shares.
  • Shares sold on September 17, 2026: 9,624 shares at a weighted average price of $67.83, and 376 shares at a weighted average price of $68.45, for a combined 10,000 shares.
  • 10b5-1 plan: All transactions were effected pursuant to a written Rule 10b5-1 plan adopted by Section Six Partners, L.P. on May 14, 2026.
  • Indirect ownership following transactions: 1,296,594 shares held indirectly through Section Six Partners, L.P., plus 163,266 shares held directly.
  • Beneficial ownership disclaimer: The reporting person disclaims beneficial ownership of shares held by Section Six Partners, L.P. except to the extent of his pecuniary interest therein.

Schmertzler's Sales Through Section Six Partners Under Pre-Set Plan

According to the filing, all four sale transactions were executed through Section Six Partners, L.P., a limited partnership in which Michael Schmertzler serves as both a general partner and a limited partner. The filing states that these transactions were made pursuant to a written Rule 10b5-1 plan that Section Six Partners, L.P. adopted on May 14, 2026. The filing box indicating a Rule 10b5-1(c) plan is checked on the form.

On September 16, 2026, the filing reports two separate sale transactions: 2,994 shares at a weighted average price of $66.58 per share, with individual trade prices ranging from $65.99 to $66.96, and 7,006 shares at a weighted average price of $67.35 per share, with individual trade prices ranging from $66.99 to $67.72. On September 17, 2026, two additional transactions occurred: 9,624 shares at a weighted average price of $67.83 per share, with trade prices ranging from $67.27 to $68.10, and 376 shares at a weighted average price of $68.45 per share, with trade prices ranging from $68.35 to $68.84.

Following all reported transactions, the filing discloses that Schmertzler beneficially owned 163,266 shares directly and 1,296,594 shares indirectly through Section Six Partners, L.P. The filing notes that Schmertzler "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." The filing was signed by Avraham S. Adler as attorney-in-fact on September 18, 2026.

What Was Disclosed

The Form 4 discloses four sales of PTC Therapeutics common stock totaling 20,000 shares by director Michael Schmertzler, conducted indirectly through Section Six Partners, L.P. on September 16 and 17, 2026, under a Rule 10b5-1 plan established May 14, 2026.