Great stock which has gotten a little over extended. I have a friend which holds a lot of NKE and I told him to take profits in Jan, which he didn't do because it kept having those pops After each drop.
With Bump & Runs; Odds are if the 50 day MA is broken on a run/retrace. (which it has) price will eventually reach previous trend line. In NKE's case, that's between $84 & $86 before it coming back alive. Want to mention one more thing to keep in mind. There is a rule of thumb with big caps that if it reaches $80, eventually it will hit $120.
So the whole thing about NKE is are you playing it long, or swing trading. Swing I'd expect a retrace to mid eighties. Long I'd expect $120 in 6 months to a year or so.