Gossamer Bio Announces 1-for-80 Reverse Stock Split

What Happened Gossamer Bio, Inc. (GOSS) filed an 8-K reporting that its Board selected a 1-for-80 reverse stock split of its common stock, effective 11:59 p.m. ET on September 10, 2026, when a Certificate of Amendment was filed in Delaware. The split-adjusted shares were expected to begin trading on the Nasdaq Global Select Market under the existing symbol “GOSS” at market open on September 11, 2026 (new CUSIP 38341P201). The company also proportionately reduced the number of authorized shares of common stock and total authorized capital stock.

Key Details

• Reverse split ratio: 1-for-80, effective September 10, 2026 (Certificate of Amendment filed in Delaware).
• Authorized shares reduced: Common stock authorized shares cut from 4,000,000,000 to 50,000,000; total authorized capital stock reduced from 4,070,000,000 to 120,000,000.
• Trading/CUSIP: Split-adjusted trading expected to begin Sept 11, 2026 on Nasdaq Global Select Market under “GOSS”; new CUSIP 38341P201.
• Securities adjustments: Conversion rates for outstanding convertible notes (including 5.00% Convertible Senior Notes due 2027 and 7.50% Convertible Senior Secured First Lien Notes due 2030), shares issuable on outstanding warrants and prefunded warrants, outstanding equity awards, and shares reserved under equity plans were proportionately adjusted.
• Fractional shares: The company will not issue fractional shares to holders; rounding to whole shares will be handled (including rounding up at the DTC participant level); brokers/nominees may apply their own procedures.
• Purpose: The Reverse Stock Split is intended to help the company regain compliance with Nasdaq’s $1.00 minimum bid price rule (must meet $1.00 for 10 consecutive business days before the compliance date of October 5, 2026). The company cautioned there is no assurance it will regain or maintain compliance.

Why It Matters A reverse stock split and reduction in authorized shares are corporate actions intended to increase the per-share trading price and help Gossamer meet Nasdaq listing standards. For investors, the split changes the share count and per-share metrics (including conversion and exercise amounts for notes, warrants and options) but does not change an investor’s proportional ownership or the company’s market value in isolation. The filing also highlights that meeting Nasdaq’s $1.00 bid-price requirement is the stated goal but is not guaranteed; continued listing, trading behavior and future volatility remain material considerations. The company issued a press release on September 11, 2026 and included standard forward‑looking statement warnings.