PTC Therapeutics (PTCT) Director Michael Schmertzler Sells Shares

What Happened
Michael Schmertzler, a director of PTC Therapeutics (PTCT), sold a total of 20,000 shares of PTCT common stock in open-market transactions on September 16–17, 2026 for aggregate proceeds of approximately $1,349,728. Transactions reported:

• 2,994 shares on 2026-09-16 at a weighted average $66.58 — $199,341 (range $65.99–$66.96).
• 7,006 shares on 2026-09-16 at a weighted average $67.35 — $471,854 (range $66.99–$67.72).
• 9,624 shares on 2026-09-17 at a weighted average $67.83 — $652,796 (range $67.27–$68.10).
• 376 shares on 2026-09-17 at a weighted average $68.45 — $25,737 (range $68.35–$68.84).
  These were sales (not purchases); sales are often routine and may not indicate company-specific views.

Key Details

• Dates: Sept 16–17, 2026; Filing date: Sept 18, 2026 (filed within the typical two-business-day Form 4 window).
• Total sold: 20,000 shares for ~ $1.35 million.
• Ownership after transaction: The filing reports these shares were held by Section Six Partners, L.P.; Schmertzler is a general and limited partner and disclaims beneficial ownership except to the extent of his pecuniary interest. The filing does not state an exact post-transaction personal beneficial share count.
• Notable footnotes: One transaction was effected pursuant to a written Rule 10b5-1 trading plan adopted May 14, 2026 by Section Six Partners, L.P. Several reported prices are weighted averages of multiple trades (breakdowns available on request as noted in the filing).

Context
A 10b5-1 plan indicates at least some trades were pre-planned and may reduce the inference that the sales reflect real-time opinions about the company. For retail investors, purchases by insiders generally carry more interpretive weight than routine sales; these transactions are documented sales by a director and were reported in a timely Form 4.