Is Amicus Therapeutics (FOLD) a Buy or Sell in a Rising Short Interest Environment?

The recent surge in short interest for Amicus Therapeutics (FOLD) has sparked debate among investors about whether the stock represents a contrarian buying opportunity or a cautionary sell signal. With the biotech sector in flux and FOLD's stock price climbing to a 52-week high following its $4.8 billion acquisition by BioMarin Pharmaceutical Inc., the interplay between bearish short-term sentiment and bullish technical indicators offers a compelling case for a nuanced investment thesis.

Contrarian Short-Interest Dynamics

Short interest in FOLD has risen to 19.31 million shares as of November 28, 2025, representing 6.40% of the publicly traded float. This marks a 7.0% increase from the previous month's 18.04 million shares according to market data, signaling heightened bearish sentiment. While such a rise might traditionally deter investors, historical context reveals a more balanced picture. Over the past year, FOLD's short interest has fluctuated between 19.98 million (7.34% of float) and 20.88 million shares (7.67% of float) as reported on Yahoo Finance, suggesting that current levels, though elevated, are not unprecedented.

The short interest ratio (SIR), or "days to cover," stands at 3.7 according to MarketBeat data, indicating that short sellers would need approximately 3.7 days to cover their positions at the current average daily trading volume. This metric, while above the 1–4 range typically associated with strong positive sentiment, still falls short of extreme levels that might trigger panic-driven short squeezes. However, the recent acquisition news has amplified volatility, with FOLD's stock surging to $14.36 on December 19, 2025, creating a scenario where short sellers face mounting pressure to cover positions-a dynamic historically favorable to bulls.

Bullish Technical Signals Amid Volatility

Technical analysis of FOLD's price action and indicators further strengthens the case for a bullish stance. The stock's 14-day RSI (Relative Strength Index) has entered overbought territory at 95, a level often associated with short-term corrections. However, this overbought condition also reflects strong momentum, which, when combined with a rising trendline, could signal a continuation of gains rather than a reversal.

The MACD (Moving Average Convergence Divergence) indicator is trending positively, issuing a buy signal. This aligns with the stock's position above both short-term and long-term moving averages, which are themselves bullish signals. While the RSI's overbought status suggests a potential pullback, the broader technical picture-particularly the stock's recent 52-week high-indicates that any correction may be shallow and short-lived.

Synthesis: A Contrarian Buy Case

The juxtaposition of rising short interest and robust technical indicators creates a fertile ground for a contrarian investment strategy. Short sellers, historically positioned as contrarian indicators, often drive prices higher when forced to cover during upward trends. FOLD's current short interest ratio of 3.7 according to MarketBeat data is moderate enough to avoid immediate panic but high enough to amplify upward pressure if the stock continues its ascent.

Moreover, the acquisition by BioMarin has fundamentally altered FOLD's valuation trajectory. While short sellers may have anticipated near-term profit-taking after the $14.36 peak according to Yahoo Finance data, the technical underpinnings-particularly the MACD and moving averages-suggest that the stock's long-term trend remains intact. A short squeeze, though not guaranteed, becomes increasingly plausible as short sellers face margin calls or forced coverings in a rising price environment.

Conclusion

Amicus Therapeutics (FOLD) presents a compelling case for a contrarian buy in a rising short interest environment. While the 6.40% short interest rate according to MarketBeat data reflects bearish positioning, historical context and technical analysis indicate that this sentiment is being outpaced by fundamental and technical strength. Investors willing to navigate short-term volatility may find FOLD's combination of a moderate short interest ratio, bullish MACD, and overbought RSI to be a powerful catalyst for further gains.