Short Interest in ProShares Ultra Nasdaq Biotechnology Surges Short interest in ProShares Ultra Nasdaq Biotechnology increased significantly by 154.5% in February, reaching 11,200 shares. This sharp rise, compared to January's 4,400 shares, suggests heightened bearish sentiment. With a trading volume averaging 10,100 shares, the days-to-cover ratio stands at 1.1 days, highlighting active market dynamics.2