SCHEDULE: Armistice Capital Discloses 4.08% Stake in PTC Therapeutics

Armistice Capital, LLC and Steven Boyd have reported a 4.08% beneficial ownership stake in PTC Therapeutics, Inc. as of September 30, 2025.

Summary

• Armistice Capital, LLC and Steven Boyd collectively beneficially own 3,277,272 shares of PTC Therapeutics, Inc. common stock.
• This ownership represents 4.08% of the company's total outstanding common stock.
• The percentage is calculated based on 80,288,306 shares outstanding as of November 3, 2025, as reported in PTC Therapeutics' Form 10-Q filed on November 4, 2025.
• Armistice Capital, LLC, acting as the investment manager, holds shared voting and dispositive power over these securities.
• Steven Boyd, as the managing member of Armistice Capital, is also deemed to beneficially own these securities.
• The shares are held in the ordinary course of business and not for the purpose of changing or influencing control of PTC Therapeutics.

Sentiment

Score: 5

Explanation: This is a routine disclosure of beneficial ownership, indicating a significant but non-controlling institutional stake. It does not inherently convey positive or negative sentiment about the company's performance or prospects, but rather a factual reporting of an investment position.

Positives

• NA

Negatives

• NA

Risks

• NA

Future Outlook

NA

Management Comments

• NA

Industry Context

This filing provides transparency into institutional holdings in PTC Therapeutics, a company likely operating in the biotechnology or pharmaceutical sector. The disclosure of a significant, albeit non-controlling, stake by an investment manager like Armistice Capital can be viewed by the market as an indicator of investor interest in the company's long-term prospects.

Comparison to Industry Standards

• NA

Stakeholder Impact

• Shareholders: Provides transparency regarding a significant institutional investor's stake, which can be viewed as a vote of confidence or a potential source of future liquidity/influence, though the stake is below the 5% threshold for more active reporting.
• Management: Awareness of a notable institutional holder, which may influence future investor relations strategies.

Next Steps

• NA

Key Dates

Keywords

PTC Therapeutics, Armistice Capital, Steven Boyd, Beneficial Ownership, Schedule 13G, Common Stock, Institutional Investor, Equity Stake