The term S&P 600 Index refers to an index that measures the performance of small-cap stocks in the United States equities market. The S&P 600 is published and maintained by S&P Dow Jones Indices.
Also known as the SmallCap 600, the S&P 600 Index was launched on October 28, 1994. The index measures the performance of small market capitalization securities traded on the United States securities markets. To be considered for inclusion in the S&P 600, the company must have an unadjusted market capitalization between $400 million and $1.8 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 600 are considerably smaller than the larger, and more stable, companies in the S&P 500.
The objective of the index is to measure the performance of small 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. 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 SML.