The healthcare sector (XLV) gained 4.91% in August, outperforming the S&P 500. Biotech led gains, with Moderna surging 156% on positive cancer vaccine trial results. Other top performers included Veeva Systems and Charles River Laboratories. Conversely, healthcare services and managed care faced pressure; DaVita was the top detractor, falling 26.7% due to dialysis business concerns and potential GLP-1 impact. Analysts note margin compression and payer mix shifts affecting laggards like CVS Health and UnitedHealth.