Earnings Rules

Hi Pat, I am a new VIP member as of today.  You made a comment in your Key List video last night about DXCM.  I had sold half of my position before earnings because I did not have a cushion of at least 20%, my rule.  I did buy back the shares I sold near the open and received the haircut you mentioned. I was wondering what rule do you use to buy back shares after earnings come out?  Thank you and looking forward to my learning with you.