Gossamer Bio (NASDAQ:GOSS) shares surged 5.28% on key clinical milestones and analyst upgrades.

Gossamer Bio Inc. (NASDAQ:GOSS) shares surged 5.28% in pre-market trading on December 16, 2025, signaling renewed investor confidence ahead of key clinical milestones. The upward momentum aligns with recent analyst activity and trial progress for the biopharma developer of inhaled seralutinib for pulmonary hypertension.

Analysts have reinforced optimism about the company’s pipeline. Piper Sandler maintained a Buy rating with a $15 price target, while Oppenheimer raised its target to $12 from $9, citing strong baseline data for the PROSERA Phase 3 trial. The trial, expected to report top-line results in February 2026, has a heightened probability of success due to favorable Phase 2 TORREY data showing significant 6-Minute Walk Distance improvements. UBS and Scotiabank also upgraded their ratings, highlighting seralutinib’s differentiated inhaled mechanism and underappreciated potential in pulmonary arterial hypertension markets.

Operational progress includes activation of the first site for the Phase 3 SERANATA/PH-ILD trial, with data expected in 2027. While Q3 2025 revenue of $13.3 million exceeded estimates, the $48.2 million net loss widened compared to prior periods. Investors appear focused on long-term catalysts rather than near-term financial metrics, as the stock’s pre-market rally suggests anticipation of upcoming trial readouts and analyst-driven valuation adjustments.

Investor sentiment appears to be driven by the broader pipeline visibility and analyst optimism. The stock’s performance is closely tied to the success of the Phase 3 trials for seralutinib, with many analysts believing that positive results could catalyze a re-rating of the company’s valuation. Meanwhile, the recent upgrades from major firms add credibility to the bullish case, reinforcing the stock as a potential deep-value play in the high-risk, high-reward biotech space.