The term S&P 100 Index refers to a subset of the S&P 500 Index that represents the leading stocks with exchange-listed options. The S&P 100 is oftentimes used for derivatives.
The S&P 100 Index was launched on June 15, 1983. The index is a subset of the more widely quoted S&P 500 Index. To be considered for inclusion in the S&P 100, the company must have an unadjusted market capitalization of at least $5.3 billion. The stock should also trade a minimum of 250,000 shares in each of the six months preceding its evaluation for inclusion in the index. The companies included in the S&P 100 are also some of the larger and more stable companies in the S&P 500. The companies must also have listed options to be considered for inclusion.
The objective of the index is to measure the performance of large cap companies located in the United States. The companies in the index are also spread across multiple industries with the goal of ensuring sector balance. While companies included in the S&P 100 represent only 25% of the listings, they account for nearly 60% of the market capitalization of the S&P 500.
Performance of the index is calculated based on market capitalization weights, which means the movement of common stocks of larger companies in the index, in terms of market capitalization, has a greater impact on the movement of the index. The index is float-weighted, meaning only the shares that are publicly traded are included in the weighting calculation. The performance of the index can be tracked using the stock ticker OEX.