I really don't put much stock in that other than it may be an indication of a shortage of shares of MM inventories. Those short positions are generally covered inter day by cross trades (One MM closing a short position by buying from another during a trading session). More significant is the monthly report at OTC Markets, which reflect end of month open short positions.
As I said before though, the report you showed indicates how thin the availability of shares are within each MM inventory. Also indicates a great deal of potential volatility, if demand rises for shares. Still Good Stuff.
WE MUST ALL REALIZE THE DIFFERENCE BETWEEN HOPE & EXPECTAION BASED ON GIVEN FACTS.