Collegium Pharmaceutical's stock plummeted 6.15% during intraday trading on Thursday, marking a significant decline for the pharmaceutical company.

The sharp drop appears to be directly related to news that Scott Dreyer, the company's Executive Vice President and Chief Commercial Officer, disposed of common shares in Collegium Pharmaceutical. Insider selling by key executives often triggers negative market sentiment as investors interpret such moves as potential lack of confidence in the company's near-term prospects or concerns about overvaluation.