I picked it up from articles I read from Daryl Guppy (google and it will come up pretty quick). I'm pretty new to this, but it looks to be usefull on occasions where the retracement goes beyond 50% but uptrend is still possible. Still playing with it and testing it out, but NVA looks like a good candidate...
As I said, I'm pretty green, so take what I say with a generous pinch of salt...
