The S&P 100 (Standard and Poor's 100) is a stock market index of United States blue chip large-cap (and/or mega-cap) stocks maintained by S&P Dow Jones Indices.
The S&P 100 is a subset of the S&P 500 and the S&P 1500, and holds stocks that tend to be the largest and most established companies in the S&P 500. However, the S&P 100 actually includes 101 larger US company stocks due to holding two different share classes of Alphabet Inc.
Constituents of the S&P 100 are selected for sector balance and represent nearly 71% of the market capitalization of the S&P 500 and 61% of the market capitalization of the U.S. equity markets as of December 2024.
Index options on the S&P 100 are traded with the ticker symbol "OEX". Because of the popularity of these options, investors often refer to the index by its ticker symbol.
Contents
History
In 1983, the CBOE created the first index options, based on its own index, the CBOE 100.
In 1993, CBOE created the Chicago Board Options Exchange Market Volatility Index (VIX), which was computed based on the price of S&P 100 options (at the time these were by far the most heavily traded index options). Then in 2003, they changed it to be based on the S&P 500.
Statistics
The mean free float market capitalization of the S&P 100 is over 3 times that of the S&P 500 ($135 bn vs $40 bn as of January 2017); as such, it is larger than a large-cap index. The volatility ("sigma") of individual companies within the S&P 100 is typically less than that of the S&P 500 and thus the corresponding volatility of the S&P 100 is lower. However, the correlation between the two indices is very high.
Investing
This index is tracked by the iShares S&P 100 ETF (NYSE Arca: OEF).
Record values
As of May 14, 2026:
Components
(as of September 22, 2025)
Annual returns
The following table shows the price return of the S&P 100 since 1975: