The short sales statistics are a little confusing. There are two types of reports--the semimonthly SHORT INTEREST report and the daily SHORT SALES report. SHORT SALES include all the shares that the MMs sell short (naked but legal for them) during the routine daily trading. That value tends to be a fairly significant percentage of the daily volume--check out the link below. It doesn't seem to relate well to the actual investor SHORT INTEREST. With short sales so large yesterday, even though it may have been the MM, it did bring the pps down late in the day. It may have also been some large investor trying to get the pps down in order to spook some others to sell out at a lower price. Today's open looks like someone is messing with us. Down premarket and at the open only to come right back with a couple of minutes.
The SHORT INTEREST from the OTC exchange shows the true number of shorted shares and has been relatively stable for several months around the 250K to 300K range (see the link below). It only comes out twice per month so large swings in the short interest could get covered before the report is generated.
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