Popcorn or sine wave?

Argument can be made that when a pair reverts to mean it will eventually follow through to the other side leading to the other extreme. I've not been following that strategy though. The stock price moves resemble more of popcorn style moves.  Also if anyone has better ideas on a close out strategy would be greatly appreciated.  Couple of things happened in the last few days. One pair hit the 7-8% threshold (UMPQ/CBU), but we didn't close out at that time and now we are back to square one. The other pair overshot our estimate (MTN/MAR) and we ended up closing out too soon...