The S&P SmallCap 600 Index (S&P 600) is a stock market index established by Standard & Poor's. It covers roughly the small-cap range of US stocks, using a capitalization-weighted index. As of 31 January 2017, the market capital of companies included in the S&P SmallCap 600 Index ranged from US$400 million to US$1.8 billion. The index's median market cap was almost $1.1 billion and covered roughly three percent of the total US stock market. These smallcap stocks cover a narrower range of capitalization than the companies covered by the Russell 2000 Smallcap index which range from $169 million to $4 billion. The market valuation for companies in the SmallCap Index and other indices change over times with inflation and the growth of publicly traded companies. The S&P 400 MidCap index combined with the SmallCap 600 compose the S&P 1000, and the S&P 1000 plus the S&P 500 comprise the S&P 1500. The index was launched on October 28, 1994.