What exactly are US futures?
If the term "US futures" is unfamiliar to you, think of it this way: an index is simply a number that represents the prices of various items combined. For example, the Nasdaq 100 is a compilation of the stock prices of the 100 largest and most traded companies listed on Nasdaq. In that case, the US futures index can be seen as a combined indicator of various US futures products. Major indices include S&P 500 futures, Nasdaq 100 futures, and Dow Jones futures.
First, the S&P 500 futures are based on the top 500 companies by market capitalization among those listed in New York and Nasdaq.