do try google, several pages out there that might explain it...

do try google, several pages out there that might explain it better.
not sure if link will work for you, here's one of many:

http://stockcharts.com/school/doku.php?id=chart_school:trading_strategies:gap_trading_strategies

it's good to familiarise yourself with them as I have seen many play out.

lemme show you one.
NCM.
Been wanting on board that but didn't wanna chase it too high.
I still reckon the share price will drop back and fill these gaps at some point, but you know, if Gold keeps on racing it may not care to retreat just now and fill at some future date.

or not