What is the US S&P 500? The Standard and Poor's 500, or simply the S&P 500 , is a stock market index that tracks 500 large companies listed on stock exchanges in the United States . [Wikipedia]. This is being used as a benchmark for the US stock market. If you invest in the S&P 500, you are technically betting on the US economy. This is just a rough guide of how you can start. There are two ways you can do this: Feeder Funds (UITFs) International Stock Brokers Feeder funds