Spero Therapeutics is trading 5.1% up at $1.23 following a modest rebound from recent weakness, likely driven by thin after-hours liquidity and technical trading interest rather than fundamental catalysts.
- No fresh company-specific news, earnings reports, or FDA updates were reported on July 31 to account for the price action.
- The stock's extended-hours move significantly outpaces broader market indices, which remained only mildly positive, suggesting the volatility is liquidity-driven.