Why Did Mustang Bio Plunge 11.68% After 196.21% Surge?

On July 8, 2025, Mustang Bio's stock price dropped by 11.68% in pre-market trading.

Mustang Bio experienced significant volatility in its stock price over the past few days. On July 7, the company's shares surged by 196.21% during regular trading hours, reaching $3.53. This dramatic increase was followed by a 7.8% decline to $3.08 during Monday's after-market session. The stock's market value of outstanding shares was reported to be at $5.2 billion.

The surge in Mustang Bio's stock price can be attributed to the company receiving orphan drug designation from the Food and Drug Administration (FDA) for one of its products. This designation is granted to drugs that are intended to treat rare diseases or conditions, and it provides certain incentives to the drug's developer, such as tax credits and market exclusivity. The news of the FDA's designation led to a significant increase in Mustang Bio's stock price, with shares more than quadrupling to $5.23.

However, the stock's price has since declined, indicating that investors may be taking profits or reassessing the company's prospects. Despite the recent volatility, Mustang Bio's stock price remains significantly higher than it was before the FDA's designation was announced. Investors will be watching closely to see how the company's product development progresses and whether it can continue to generate positive news and momentum.