After trading the index futures for 2 years, I get a feeling that the indices that contain many stocks e.g. SP500, are usually rather choppy and their trends are usually short-lived . Indices contain fewer stocks e.g. DOW(30), STOXX50, usually move quite smooth and their trends can last longer. I think they may need different trading systems. But I cannot prove it mathematically, it is only my gut feeling. If my feeling is correct, the Narrow-Based Indices futures planning by the OneChicago should be quite attractive if the liquidity is OK. I welcome any comment.