what is spx

SPX refers to the S&P 500 index, which is a stock market index that measures the performance of 500 large cap publicly traded companies in the United States. It is a theoretical index, meaning that its value is not based on a held portfolio of stock shares, but is instead pegged to the value of the S&P 500. SPX options are available for investors to buy and sell, which function as bets on whether the price of the index will increase or decrease. SPX is not an ETF that is backed by actual shares of stock in the companies that are listed on the S&P 500, unlike SPY.