This Fund Sold $30 Million in PTC Therapeutics Shares Amid a 93% Rally: Here’s Why

As reported in an SEC filing on Friday, New York City-based Armistice Capital sold 1,458,192 shares of PTC Therapeutics (NASDAQ:PTCT) during the third quarter, reducing its position by $30.2 million in value.

What Happened

According to a filing with the U.S. Securities and Exchange Commission released on Friday, Armistice Capital reduced its stake in PTC Therapeutics (NASDAQ:PTCT) by nearly 1.5 million shares in the third quarter. The position now stands at 3.3 million shares worth $201.1 million as of the quarter’s end.

What Else to Know

The trade was a reduction; the holding now represents 2.5% of Armistice’s 13F reportable assets

Top holdings after the filing:

• NASDAQ:PTCT: $201.1 million (6.3% of AUM)
• NASDAQ:TVTX: $160.7 million (5% of AUM)
• NASDAQ:SUPN: $135.5 million (4.3% of AUM)
• NASDAQ:INCY: $99 million (3.1% of AUM)
• NASDAQ:NBIX: $97.8 million (3.1% of AUM)

As of Monday's market close, shares of PTC Therapeutics were priced at $75.60, up 93% over the past year and far outperforming the S&P 500, which is up nearly 14% in the same period. The position was previously 3.2% of the fund’s AUM as of the prior quarter.

Company Overview

Company Snapshot

PTC Therapeutics, Inc. is a biopharmaceutical company specializing in innovative therapies for rare diseases, with a diversified portfolio of commercial products and a robust research pipeline, including Translarna and Emflaza for Duchenne muscular dystrophy, and markets additional treatments such as Tegsedi, Waylivra, and Evrysdi for rare diseases in select global regions. The company leverages strategic collaborations and global market access to address unmet medical needs in rare and orphan disease populations.

Foolish Take

Armistice’s move is worth watching because it illustrates how an event-driven healthcare fund manages oversized positions amid major inflection points. PTC Therapeutics just delivered one of its strongest quarters, driven by the global launch of prescription drug Sephience and a dramatic swing to profitability. With total revenue rising to $211 million and net income turning positive at $15.9 million—compared with a $106.7 million loss a year ago—the stock’s 93% rally over the past 12 months materially expanded the fund’s exposure. Trimming the position here looks more like portfolio discipline than a change in thesis.

PTC’s balance sheet also improved sharply. Cash and marketable securities climbed to $1.69 billion, boosted by upfront payments tied to Sephience. Meanwhile, early launch indicators were strong: Sephience generated $19.6 million in Q3 revenue, with 521 patient start forms in the U.S. from 141 prescribers. Meanwhile, royalty revenue from Evrysdi also grew, reaching $70.8 million for the quarter.

Even after selling 1.5 million shares, Armistice still holds 3.3 million, making PTCT its single largest position at 6.3% of AUM—consistent with its strategy of concentrated event-driven bets across rare disease leaders. Ultimately, PTC’s commercial traction and expanding profitability justify sustained institutional interest. The path ahead hinges on regulatory milestones and sustained Sephience adoption.

Glossary

AUM (Assets Under Management): The total market value of investments managed by a fund or investment firm.
13F reportable assets: Securities holdings that institutional investment managers must disclose quarterly to the SEC using Form 13F.
Alpha: A measure of an investment's performance compared to a benchmark, indicating outperformance or underperformance.
Quarter’s end: The last day of a financial quarter, used as a reference point for reporting financial data.
Stake: The ownership interest or number of shares held in a company by an investor or fund.
Reduction (in position): Selling part of an investment, resulting in a smaller ownership stake.
Pipeline (in pharmaceuticals): The portfolio of drug candidates a company is developing, from early research to clinical trials.
Orphan diseases: Rare medical conditions affecting a small percentage of the population, often lacking effective treatments.
Commercializes: Brings products, such as drugs, to market for sale and revenue generation.
Strategic collaborations: Partnerships between companies to achieve shared business or research goals.
TTM: The 12-month period ending with the most recent quarterly report.

Jonathan Ponciano has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Incyte. The Motley Fool recommends Neurocrine Biosciences. The Motley Fool has a disclosure policy.