Short Interest in STF Tactical Growth ETF Surges 4,200% in February Short interest in the STF Tactical Growth ETF (NASDAQ:TUG) experienced a dramatic rise in February, increasing by 4,200% to 8,600 shares as of February 28. Despite this surge, shorted shares only account for 0.2% of the ETF's total. With an average daily trading volume of 16,000 shares, the days-to-cover ratio remains low at 0.5 days.1