Why Is GOSSAMER BIO INC (GOSS) Stock Moving Today?

Gossamer Bio (GOSS) stock is moving sharply higher today after the company executed a 1-for-80 reverse stock split and share reduction. The stock opened at $8.03, a 5,539.1% increase from the prior close of $0.14, and reached a session high of $13.25 shortly after the market opened. The move is tied to the company’s announcement that the reverse split became effective on September 10, reducing authorized shares from 4 billion to 50 million.

What Happened

Gossamer Bio implemented a 1-for-80 reverse stock split on September 10, 2026, as disclosed in an SEC 8-K filing on September 11. The company also announced that its stock must close at or above $1 for at least 10 consecutive business days to regain compliance with listing requirements by October 5. The stock was halted before the market opened, with news pending, and reopened at a significantly higher price. The reverse split is part of a broader effort to restructure the company’s capital and meet regulatory requirements.

What The Data Shows

Intraday trading showed a dramatic gap up, with the stock opening at $8.03 and reaching $13.25 within minutes. The 52-week range for the stock is $0.11 to $3.87, indicating the current price is well above historical levels. Over the last eight sessions, the stock had declined 17.0% from $0.22 to $0.18. There has been no significant social media chatter in the last 24 hours, and only one post in the last seven days.

What To Watch

The stock will continue to be monitored for its ability to maintain a price above $1 for 10 consecutive business days to meet compliance goals. Investors should also watch for further updates on the company’s $250 million structured private placement and any upcoming FDA milestones that may impact its financing plans.