S&P 500 Index is the ultimate benchmark of the US economy, featuring 500 of the largest and most influential publicly traded companies. Often called 'the market’s heartbeat,' it is a market-cap-weighted index that represents approximately 80% of the…
Category
Stock index
Currency
USD
S&P 500 — Quick Facts
Weighting method | Float-adjusted market cap weighted |
Rebalance schedule | Quarterly (Mar / Jun / Sep / Dec) |
Calculation | Real-time |
Index launched | Mar 4, 1957 |
Historical data from | Jan 3, 1928 |
Min. market cap (approx.) | $22.7Bas of Jul 1, 2025 |
SPX Analysis Tools & Insights
Returns
Daily Patterns
Index Composition