The Health Care Select Sector Index is a stock market index that tracks the performance of companies in the health care sector. This includes businesses involved in pharmaceuticals, biotechnology, medical devices, and health care services. The index is part of the broader S&P 500 and provides investors with a way to gauge the health care industry's performance. Investors often use the Health Care Select Sector Index to diversify their portfolios or to gain exposure to the health care market. It includes well-known companies like Johnson & Johnson and Pfizer, making it a popular choice for those interested in health-related investments.