I had bought Tableau Software on the May 8 gap-up...and I was up over 17% from that point going into earnings. I like to have at least a 10% profit cushion going into earnings or I sell. I've been bitten by earnings disappointments too many times.

 

Well, this morning, I woke up to find DATA gapped down and my 7% stop-loss triggered, breaking one of the CAN SLIM rules: never let a significant gain turn into a loss. Upon reflection, I should have raised my stop loss as my profit cushion increased.

 

Lesson learned...too bad most of the lessons with stock investing are costly ones.