I know that its a usable tool, but nobody can ever say that they actually know why it works. It just generally works. The key thing is not to "guess" at what is going to happen.
There are several basic levels, and you have to realize that, at any given price pullback, you have another that could be what happens next.
For example, lets say the chart wave pulls back to the 382 level. OK. Thats a major Fib number. But there is a 50%, a 618, and a 786 looming beklow. So how does anyone ever know if the wave will hold at 382? Or 618? Or 786?
The only way to do it, IMHO, is as afollower of the action. In my experience, every time I ever got out in front of the behavior and tried to guess the hold was going to be at approx 618, I 9 times out of 10 get burned.
What I do is I watch volume. Generally, when you see a wave coming down thruogh 382, 618 & so forth, what to watch for is the point at which buying comes back in.
What I do is I put up charts in different minute ranges... 5 minut, 1 minut, 10 minute... and so forth.
And I watch the VOLUME at the 382, 618 and so forth.
When I see a wave point find a toe hold based on volume, thats when I pay attention. To guess is no better than gambling. To employ a volume based approach is NOT.
So I watch volume behavior in multiple timeframes to see if I can ascertain when the PROs have stepped back in.
Hope this helps.
Imperial Whazoo