Since some post were about me, let me clarify some aspects: I can make a decent profit if there's at least 3% difference between two local
minimums / maximums, considering a 0.8% (2x 0.4%) commission and adequate volume (which has been a problem lately on Gox).
But my biggest problem is catching the peaks and bottoms while I am not sleeping, because guessing the precise values for the peaks and
bottoms is bloody difficult for me (to place an order overnight). I moved to Gox from Bitstamp because of the higher volumes, but in the
meantime that advantage of Gox has diminished. I also can't do delayed arbitrage anymore (obviously), so I might move back to Bitstamp.
It was easy to reach their 0.5% (2x 0.25%) commission, on Gox to reach 0.6% (2x 0.3%) I'd have to almost double my trades, can't do that yet.
Short term trading would be much easier if we didn't need sleep. But in light of the reality of my human form, and the fact I don't want to spend all day on the computer, I trade on longer time frames
.