E-mini futures are a great instrument, but the problem is that a single contract is creating exposure to roughly 50K of the S&P. The problem? Lack of flexbility in position sizing, scaling in and out, risk control, etc. I have no doubt that this is one reason why leveraged ETFs like SSO are now trading 10s of millions of shares a day. I've suggested to the CME that they create a half-Emin (mini/mini?) to provide more flexibility for independent traders and smaller firms. If you agree, then drop a line to the CME suggesting that they look into it.