I'm also playing around with a silent buy / sell system, that allows you to pre & post-purchase based on already declared forecasts, 24hrs in advance. If your forecast works out, you can make it stick to your portfolio... if not, wipe it out. You still make or lose money at times in the silent mode, but it gives an interesting twist when you're not online to do things live.
Unsure how manipulative it is at present... and may kick it to the curb... may release it.