S&P 500

What is the S&P 500?

The S&P 500 is a stock market index of about 500 large US companies, chosen by a committee at S&P Dow Jones Indices and weighted by company size. It covers roughly 80% of the value of US stocks, so it is often used as shorthand for the market.

A basket of many pebbles

About 500 large US companies, weighted by size

What it is
An index of about 500 large US companies, picked by a committee at S&P Dow Jones Indices.
How it is weighted
By company size, so the largest companies move it most.
How people invest in it
Through an index fund or ETF that holds the same companies.

1You cannot buy the index itself

You buy a fund that tracks it. Many index mutual funds and ETFs hold the same 500 companies.

2Big companies matter most

Because it is weighted by size, a handful of the largest companies make up a large share of the index.

3It is not the whole market

It leaves out smaller US companies and all non-US companies. Total market and international funds cover those.

4It goes down too

The index has had years with large losses. Money you need within a few years usually belongs in savings.

How to do it in Oaktally

An index fund is one holding. Oaktally shows its value beside your cash and debts.

  1. Add the accountAdd your brokerage account and its value.
  2. Track holdings on PremiumAdd the funds or stocks you own; Premium prices them with each market close.
  3. See it in your net worthHome counts it beside your cash and debts.
Get personal early access
Oaktally Home: net worth of $4,552.10 with its one-month history, assets and debts.

Frequently asked questions

Is the S&P 500 the same as the Dow?

No. The Dow Jones Industrial Average tracks 30 large companies and is weighted by share price, not company size.

How often does the S&P 500 change?

The committee adds and removes companies as they grow, shrink or are bought.

Further reading

S&P Dow Jones Indices: S&P 500 ↗

Educational examples, not individual financial advice.

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