Welcome to this week's installment of "The Short Interest Report" - The Fly's weekly recap of short interest trends among some of the most widely followed high-short-float stocks. Using the data from our partner Ortex.com, which utilizes the latest information from stock lenders to estimate short interest changes for thousands of publicly traded companies, this report will screen for some of biggest changes in short interest as a percentage of free float and days-to-cover ratios while also considering the short interest data on some of the more volatile and heavier-traded names of the week. Based on the availability of data from Ortex, the report tracks the trading period that covers prior Friday through Thursday of this week, excluding holidays. As a basis of comparison for stocks discussed below, the S&P 500 index was down 3.0%, the Nasdaq Composite was down 2.6%, the Russell 2000 index was down 5.9%, the Russell 2000 Growth ETF (IWO) was down 4.6%, and the Russell 2000 Value ETF (IWN) was down 6.3% in the five-day trading session range through December 19.