The S&P 500 is a stock market index of the 500 largest US public companies by market capitalization, weighted by market cap. It's the most widely cited barometer of the US stock market. To be included, a company must meet criteria for size, liquidity, financial viability, and US headquarters. The index represents about 80% of total US stock market value. Popular S&P 500 ETFs: VOO (Vanguard, 0.03% expense), IVV (iShares), SPY (oldest, most liquid). Historically, the S&P 500 returns about 10% annually before inflation, with significant year-to-year volatility. It's the standard benchmark most active fund managers fail to beat.
Article
401(k)
A 401(k) is an employer-sponsored retirement plan where employees contribute pre-tax salary that grows tax-deferred until withdrawal. The…
Active Management
Active management is the attempt to outperform a benchmark through stock selection, sector rotation, market timing, or any…
Alpha
Alpha is excess return relative to a benchmark, adjusted for risk (beta). Positive alpha means an investment outperformed…
Asset Allocation
Asset allocation is the percentage split of your portfolio across asset classes — typically stocks, bonds, and cash,…
Backdoor Roth
The Backdoor Roth is a strategy for high earners (above the Roth IRA income limit) to contribute to…
Beta
Beta measures a stock's volatility relative to the overall market (S&P 500 = beta of 1). Stocks with…
S&P 500
August 22, 2026 · Aditya Gupta
Investing
Related terms
401(k)
A 401(k) is an employer-sponsored retirement plan where employees contribute pre-tax salary that grows tax-deferred until withdrawal. The…
Active Management
Active management is the attempt to outperform a benchmark through stock selection, sector rotation, market timing, or any…
Alpha
Alpha is excess return relative to a benchmark, adjusted for risk (beta). Positive alpha means an investment outperformed…
Asset Allocation
Asset allocation is the percentage split of your portfolio across asset classes — typically stocks, bonds, and cash,…
Backdoor Roth
The Backdoor Roth is a strategy for high earners (above the Roth IRA income limit) to contribute to…
Beta
Beta measures a stock's volatility relative to the overall market (S&P 500 = beta of 1). Stocks with…
