Quote from Bombardier:
You point out a very valid issue, gmst. Position scaling is something I will have to deal with in the near future once my accumulated profits justify an upgrade. When I traded CFDs and ETFs back then (which allow very flexible scaling in small amounts), I haven't had much success with adding to a position. The market usually turned against me the moment I increased, so I was always better off if I hadn't done anything. I'm sure there are traders who do it successfully, and I would like to hear their thoughts. As far as I am concerned, I find scaling out a more relevant tactic to explore.
Let me repeat: you should read "Way of the Turtles" by Curtis Faith, at the earliest. If you haven't read that already. You may find answers to a lot of questions there and definitely interesting approaches.
