These contracts allow market participants to gain exposure to price fluctuations in the S&P 500, Russell 2000, Dow Jones 30 and Nasdaq100 indices at a much lower cost than the existing e-mini futures. Depending on which broker you use, you can go long or short markets like the S&P500 http://claytonlfxqi.tinyblogging.com/What-Are-Micro-E-Mini-Futures--47447418