Why Amylyx Pharmaceuticals (AMLX) Stock Soared on Tuesday

Shares of Amylyx Pharmaceuticals (NASDAQ: AMLX) skyrocketed on Tuesday, closing at $35.11 — up roughly 64% from Monday’s close of $21.43 — as trading volume surged to nearly 23.8 million shares, almost 20 times its recent daily average.

The stock touched a fresh three-year high during the session before settling near the top of its intraday range of $28.00 to $35.39.

The catalyst was overwhelmingly positive data from Amylyx’s Phase 3 LUCIDITY trial evaluating avexitide, an experimental GLP-1-related therapy for post-bariatric hypoglycemia (PBH) — a serious and currently untreated complication that can affect patients who have undergone weight-loss surgery.

The company announced that the trial met its FDA-agreed primary endpoint, with avexitide reducing the incidence of severe hypoglycemic events by 55% compared to placebo, a result investors and analysts viewed as clinically meaningful and statistically robust.

Because PBH currently has no FDA-approved treatments, the strong efficacy signal significantly de-risks avexitide’s path toward a potential regulatory filing and commercial launch, opening what analysts estimate could be a lucrative, underserved market. Several Wall Street analysts reiterated bullish stances following the announcement, with some retail-oriented estimates suggesting further upside potential from current levels.

The rally also comes against the backdrop of a broader healthcare sector uptick Tuesday, though Amylyx’s move was clearly company-specific and news-driven rather than a sector-wide beta effect.

Investors will now watch for regulatory next steps, including potential discussions with the FDA regarding a submission timeline, as Amylyx looks to capitalize on the positive trial outcome and diversify beyond its earlier ALS drug setback.