I don't trade much on popular technicals but sometimes I use gaps as targets but what I never understood is the theory that almost all gaps eventually get filled. Is there any sort of rationale that makes sense for this theory? In my opinion, which is the same opinion I have in regards to most technicals that the majority of the public use is that it's a simplistic theory. #1 it looks like a good target zone because it stands out in a big way on the chart. #2 I wouldn't be surprised if most gaps eventually do fill but that is more likely because markets back and fill a lot more than people realize.