Handling Gap Ups

Good Evening Pat,
Thank you for all you do and the great service you provide.  All of us really appreciate it!
I was wondering if you could make a video on gap ups, in the market and in stocks, like we experienced today on the indices and in BIDU.  
Your guidance kept me out of BIDU, but I was wondering if you could explain what is going on during gap ups, why the indices open higher, and why it is best to wait at least an hour to see how the market will handle the gap up.
This topic baffles me and I could really use some guidance.
Thank you!  John