Geron's stock plummeted 6.55% during intraday trading on Monday, following the company's regulatory filing for a new stock offering.

The biopharmaceutical company filed an automatic mixed securities shelf registration with the SEC, including a sales agreement prospectus covering the offering of up to $150 million of common stock that may be issued from time to time.

Such shelf offerings typically allow companies to sell securities over time, and the announcement of a potential equity raise often leads to investor concerns about share dilution, which appears to have driven the stock's decline in today's session.