Health stocks are experiencing their worst week since October 2020, with the Health Care Select Sector SPDR Fund (XLV) down 5.3%. This decline marks the most significant downturn for health stocks in over four years, coinciding with high trading volumes. Additionally, the iShares Nasdaq Biotechnology ETF (IBB) has faced one of the worst weeks in its history, indicating broader challenges within the biotech sector. The downturn is notable as it follows a period of relative stability in the health sector, raising concerns among investors about future performance.