Capricor Therapeutics (CAPR) saw its shares plummet 10.65% during Thursday's intraday trading, extending a pre-market decline of 8.11%. The sharp drop follows a staggering 399% surge in the previous session after the company announced positive Phase 3 trial results for its Duchenne muscular dystrophy (DMD) treatment, Deramiocel.

The decline is attributed to profit-taking by investors who capitalized on the stock's unprecedented gains. The HOPE-3 study for Deramiocel met both primary and secondary endpoints, demonstrating significant skeletal and cardiac benefits for patients, which had initially fueled the rally. Nippon Shinyaku, which plans to market CAP-1002 in the U.S. if approved, also validated the results.

The volatility underscores the market's reaction to breakthrough clinical outcomes and subsequent investor behavior, with traders locking in profits after the historic surge.