Olema Pharmaceuticals, Inc. (NASDAQ: OLMA) experienced a significant after-hours plunge of 5.66% on Tuesday, following a day of substantial gains. The biotech company, which focuses on developing therapies for women's cancers, saw its stock price decline sharply after the regular trading session ended.

Two key factors appear to be contributing to this sudden downturn. First, Olema Pharmaceuticals announced the termination of its ATM (At-The-Market) Prospectus for common stock dated January 6, 2025, as per an SEC filing. This move could be interpreted by investors as a signal that the company is shifting its capital-raising strategy, potentially impacting its financial flexibility.

Adding to the downward pressure, notorious "Pharma Bro" Martin Shkreli publicly declared a short position in Olema stock earlier in the day. Shkreli, known for his controversial market moves, expressed skepticism about Olema's valuation in light of recent positive results from a competitor's breast cancer drug trial. "Shorting OLMA, don't see how another company's results are 3x another SERD company. a million SERDs out there," Shkreli posted on social media, referring to Selective Estrogen Receptor Degrader (SERD) treatments.

The after-hours decline comes as a stark contrast to Olema's performance during regular trading hours, where the stock had surged by over 140% following positive Phase 3 results from Roche's giredestrant in early-stage breast cancer. While these results initially boosted investor confidence in SERD treatments, including Olema's pipeline, the combination of the ATM Prospectus termination and Shkreli's bearish stance appears to have prompted a sell-off in extended trading.