Short interest was only 617,256 shares that settled on 6/4/13 as reported on OTCBB. Based on avg daily volume of 4,864,463 shares, it would only take one day to cover for those shares.
However, I've been told OTC report is not reliable since OTC is not regulated. Next settlement date of June 28 will not be published until July 10. "0" short interest was reported prior to June 4.
By the way, total share volume from Knight Capital America in June was 23 million, almost twice the volume from any other MM. Isn't Knight the MM that caused a halt on NY stock exchange?