The S&P 500 (Standard and Poor's 500) is the benchmark stock market index of the United States, comprising 500 of the largest publicly listed companies on the NYSE and NASDAQ, selected by a committee based on market capitalisation, liquidity, sector representation, and financial viability. The index uses a free-float market capitalisation weighting methodology and is widely regarded as the most comprehensive and representative measure of US equity market performance. For Indian investors, the S&P 500 is highly relevant because US market movements — driven by Federal Reserve policy, US GDP data, technology sector earnings, and geopolitical developments — have a significant correlation with Indian equity markets through FPI flows, global risk sentiment, and rupee-dollar dynamics. India-listed ETFs and mutual fund FOFs (Fund of Funds) that invest in S&P 500-tracking funds are available to Indian investors seeking international diversification. The S&P 500's performance also sets the global risk appetite tone that influences Nifty 50 direction on a daily basis.