Amylyx Pharmaceuticals' stock plummeted 5.52% during intraday trading on Tuesday, following the company's announcement of a mixed securities shelf offering.

The biotechnology firm filed for an automatic mixed securities shelf offering, which typically allows companies to sell various types of securities in the future without having to file separate registration statements for each offering. While the size of the offering was not disclosed, such filings often raise concerns about potential shareholder dilution, which can lead to downward pressure on stock prices.

The price movement occurred despite Amylyx reporting fourth-quarter financial results that showed some improvement, including a smaller-than-expected net loss of $32.999 million compared to analyst estimates of a $37.1 million loss. The company also reported having $317 million in cash and investments, with a cash runway expected to extend into 2028.