Came accross an expression some years ago: "the traders experience is proportional to the barlength traded". The shorter the timeframe the more execution speed gets in the way and the more you compete with robots and specialists. And they will throw every trick in the book at you to get your moeny. The slightest mistake and you give the profits of the last x(x) days back. Jesse Livermore mentioned the same thing in his book. If it had not been for the tricks of the bucket shops he would have been happy to play the intraday fluctuations. vital analitics