Citron Research

Citron Research is an influential investment research firm and activist short-seller founded by Andrew Left. The firm is widely recognized in the biotechnology and pharmaceutical sectors for its investigative reports that often allege corporate fraud, unsustainable drug pricing models, or mismanagement, most notably its 2015 exposé on Valeant Pharmaceuticals. While not a life sciences company itself, Citron's publications have historically triggered significant volatility in healthcare stocks, leading to major regulatory investigations and substantial market revaluations. In recent years, the firm has shifted its focus toward long-side recommendations and has faced significant legal challenges from the SEC and DOJ regarding its trading practices.