It has to be read in the context of your time frame and method.
Back testing YOUR system (not someone else's) will answer that query for you.
It pays in my system not to trade gaps as often price will retrace quickly. Gaps can indicate exhuberance which can mean tops but also indicate a new trend starting off so needs to be read in contect of how mature the trend is at that point in time of the gap.
I prefer to wait after a gap, gaps can often be filled.