How do you read S&P 500?

Since it weighs by value, a few very large companies drive much of it. Its return is the benchmark for the picks' returns in the track record.

S&P 500

Market and results

The index of about 500 of the largest listed US companies, the usual yardstick for the US market.

How it is worked out

Each company counts in proportion to the value of its freely traded shares. Here it is measured through the SPY ETF, which tracks it.

How to read it

Since it weighs by value, a few very large companies drive much of it.
Its return is the benchmark for the picks' returns in the track record.

Example

A company worth 7% of all the index's companies counts for 7% of its move.

Related terms

The other pages on US stocks, free to read. On the company pages, the last three fiscal years are open to everyone, five with a free account, and every year with Ploutos Investor.

US stocksThe market today, the sectors, the largest companies and the week's results.The market's sectorsThe 11 sectors side by side: returns, share of the market, median P/E and dividend.Compare stocksTwo companies side by side: price over up to ten years, with and without dividends, and every figure.US dividend stocksEach dividend's yield next to whether the company's cash covers it and whether it was ever cut.

Explanations of terms for learning, with examples from SEC filings.