The SSPL (Standard & Poor's 500 Index) is a widely recognized and widely tracked index of 500 large-cap U.S. stocks. It is a good representation of the overall U.S. stock market and is often used as a benchmark for investment performance.
As for whether it is "worth buying," that depends on your investment goals, risk tolerance, and time horizon. The SSPL is a passive investment, meaning it tracks the performance of the underlying stocks and does not require a fund manager to pick individual stocks. This can be a low-cost and straightforward way to gain exposure to the U.S. stock market. However, it may not outperform actively managed funds, and the returns will be influenced by market conditions.
If you are looking for a diversified investment in the U.S. stock market, the SSPL could be a good option. However, it is important to consider your individual circumstances and consult with a financial advisor before making any investment decisions.