S&P 500: The Pulse of the US Economy

If you follow investment news globally, you’ve likely heard of the S&P 500. Often called the pulse of the US economy, it represents about 80% of the US stock market’s value. The S&P 500 is a market index listing the 500 largest US companies.

Investors can’t invest directly in the index but can invest in the companies through stocks or index funds. For analysts, policymakers, and investors, it serves as a benchmark to track overall market trends across sectors.

This article explains what the S&P 500 is, how it’s calculated, its limitations, competitors, and investment options.

Table of contents

• What is the S&P 500 Index?
• How the S&P 500 is calculated
• Competitors of the S&P 500
• S&P 500 vs Vanguard 500 Fund
• Limitations of the S&P 500

What is the S&P 500 Index?

The S&P 500 (Standard & Poor’s 500 Composite Stock Price Index) was launched in 1957 and became a key benchmark by 1968. It represents 500 of the largest US companies and reflects overall market performance. When the index rises, the combined value of these companies increases, and vice versa.

Covering about 80% of the US stock market’s total capitalization, it provides a diversified view of economic health across multiple sectors.

How the S&P 500 is calculated

The S&P 500 uses the free-float market capitalization method, counting only shares available for public trading and excluding those held by company promoters or insiders.

Formulas:

• Market capitalization = Outstanding shares × Current market price
• Free-float market cap = Market cap × Investible Weight Factor (IWF)
• Index value = Total free-float market cap ÷ Divisor

The divisor is adjusted for changes like new companies, buybacks, or mergers, keeping the index focused on price movements rather than structural changes.

The index does not include dividends; the S&P 500 Total Return Index (SPTR) accounts for dividend income. A company’s weight in the index shows its influence—larger weights affect the index more.

Read Also: How to Invest in US Stocks via Mutual Funds in India?

Competitors of the S&P 500

• Dow Jones Industrial Average (DJIA): Tracks 30 major industrial companies; price weighted.
• Nasdaq Composite: Includes ~3,000 Nasdaq-listed companies, mainly tech and growth-oriented.
• Russell 1000 & 2000: Russell 1000 tracks large caps; Russell 2000 focuses on small caps.

S&P 500 vs Vanguard 500 Fund

The Vanguard 500 Index Fund mirrors the S&P 500 by investing in the same stocks in roughly the same proportions, with only minor deviations.

Limitations of the S&P 500

• Large-cap bias: Ignores small and mid-sized companies that may outperform at times.
• Market-cap weighting: Big companies influence the index more, affecting overall results.
• No international diversification: Only includes US-based companies.
• Sector concentration: Certain sectors (like tech or healthcare) can dominate temporarily.

Read Also: Global ETFs: Meaning, Benefits and How to Invest?

Conclusion

The S&P 500 is a key benchmark reflecting the performance of 500 of the largest US companies, covering about 80% of the country’s stock market. It provides a diversified view of economic health across sectors, using a free-float market capitalization approach.

While it mainly tracks large-cap firms and excludes international diversification, it remains widely followed by investors, analysts, and policymakers. Though you cannot invest directly in the index, exposure is possible through index funds, ETFs, or SEBI-regulated mutual funds for Indian investors. Overall, the S&P 500 offers a reliable measure of the US large-cap market.

FAQs

Why is it called Standard and Poor’s?

It comes from two companies that merged: Standard Statistics Company (1906) and Poor’s Publishing (19th century).

Which companies qualify for the S&P 500?

• US-based
• Minimum market cap
• High liquidity
• 50%+ publicly traded shares
• Positive earnings in the latest quarter and over the past four quarters

How can you invest in the S&P 500?

• Indirectly: Through index funds or ETFs tracking the S&P 500, including Indian mutual funds or feeder funds (regulated by SEBI).
• Directly: Via US ETFs under the Liberalised Remittance Scheme (LRS), subject to regulatory, tax, and currency rules.

Popular S&P 500 index funds:

• Vanguard 500 Index Investor Shares (VFINX)
• Fidelity 500 Index Fund (FXAIX)
• Schwab S&P 500 Index Fund (SWPPX)
• T. Rowe Price Equity Index 500 Fund (PREIX)

Mutual Fund investments are subject to market risks, read all scheme related documents carefully.

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