GRAIL, Inc. (GRAL) shares tumbled 6.35% in pre-market trading on Friday following the company's announcement of a potential $300 million common stock offering. The move has sparked concerns among investors about potential share dilution, leading to a significant sell-off.

According to a SEC filing, GRAIL has entered into an equity distribution agreement with Morgan Stanley and TD Securities, allowing the company to sell up to $300 million of its common stock from time to time. The offering, which may be conducted as an "at the market" offering, could result in the issuance of up to 6.9 million new shares at a par value of $0.001 to the sales agents.

In addition to the new offering, GRAIL has also filed a prospectus supplement for the resale of approximately 3.9 million shares of its common stock, including shares issuable upon the exercise of pre-funded warrants. These shares were originally issued in a private placement dated October 18, 2025. While this resale registration doesn't directly impact the company's outstanding share count, it does increase the potential supply of shares in the market, which may be contributing to the downward pressure on the stock price.