Gaps can mean different things, depending on the type of gap. For example, "runaway" gaps are usually not filled. The gaps you suggested are likely that..runaway gaps, when fannie pushed up from about 1.05 to 2.73 in just a couple months....on good news, mostly Watt getting out, and Calabria nomination along with some great opinions by Mnuchin, Calabria, etc. See more here: https://www.investopedia.com/terms/g/gap.asp