Visit the full analysis for the latest explanation of SPDR S&P Biotech ETF's stock movement.
XBI is the SPDR S&P Biotech ETF, an equal-weighted fund tracking U.S. biotechnology companies. Its equal-weight methodology gives it higher exposure to small- and mid-cap biotech names compared to market-cap-weighted alternatives, resulting in notably higher daily volatility. Today's move tracked a broad equity rally rather than any biotech-specific development.