89bio Soars 85% on $1.2B Surge to 78th Most Traded U.S. Stock as Speculation Swirls

On September 18, 2025, , . . equities, reflecting heightened investor attention following recent developments.

Analysts noted the sharp volume spike could be attributed to strategic updates in the company’s pipeline, though specific catalysts remain undisclosed. The surge aligns with a broader trend of biotech firms attracting renewed institutional interest amid shifting market dynamics. However, the lack of disclosed fundamentals suggests the move may be driven by short-term speculative positioning rather than long-term value re-rating.

To conduct a precise back-test, several parameters require clarification: the stock universe (U.S. exchanges by default), execution timing (close-to-close or open-to-close), (equal-weight across 500 stocks), and whether or liquidity constraints should be factored. A benchmark comparison to SPY or another index is optional but recommended for context. Finalizing these details will enable accurate performance evaluation against the specified criteria.