Planet Fitness investors sue over 31.19% one-day stock drop after guidance cut

A proposed securities class action against Planet Fitness, Inc. has now been publicized by Rosen Law Firm in addition to earlier notices from Robbins LLP and The Portnoy Law Firm, broadening publicity around investor claims tied to the company’s May 2026 guidance reset. Rosen said the case covers purchasers of Planet Fitness common stock between November 6, 2025 and May 6, 2026, inclusive, and that investors have until September 14, 2026 to move for appointment as lead plaintiff. The suit follows Planet Fitness’s May 7, 2026 first-quarter results and updated full-year outlook, when the company said 2026 had started more slowly than expected from a net member growth perspective because of internal and external headwinds during its peak sign-up period. Planet Fitness also said it was pausing its planned national Black Card price increase pending a broader pricing review and lowered several 2026 targets, including system-wide same club sales growth to about 1% from 4% to 5%, revenue growth to about 7% from about 9%, adjusted EBITDA growth to about 6% from about 10%, adjusted net income to a decline of about 2% from prior guidance for 4% to 5% growth, and adjusted diluted EPS growth to about 4% from 9% to 10%. Shares fell $19.95, or 31.19%, to close at $44.01 on May 7, 2026. Rosen’s notice says defendants are accused of misleading investors about customer acquisition and marketing metrics, alleging updated marketing messaging failed to connect with and instead intimidated fitness beginners and casual gym-goers, hurting net member joins during the key first-quarter sign-up period and undermining the company’s 2026 guidance, long-term targets and Black Card pricing plans.