I've always wondered the same thing myself. I think some sites, FinViz in particular, just must not update numbers.
Morningstar shows a little more detail, but it shows a bunch of institutions that sold, but most of those dates were as of 6/30/2015, so that is older info, and wouldn't explain how sites like iHub and Morningstar themselves were showing ~60% ownership in August.
As for Nasdaq always being so low, I started to wonder if they are only looking at shares traded on the AMEX/NYSE MKT, and not the whole picture.