In trading on Tuesday, shares of the Proshares UltraPro Short QQQ ETF ( SQQQ) entered into oversold territory, changing hands as low as $14.48 per share. We define oversold territory using the Relative Strength Index, or RSI, which is a technical analysis indicator used to measure momentum on a scale of zero to 100. A stock is considered to be oversold if the RSI reading falls below 30.In the case of Proshares UltraPro Short QQQ, the RSI reading has hit 28.8 — by comparison, the RSI reading for the S&P 500 is currently 71.5. A bullish investor could look at SQQQ's 28.8 reading as a sign that the recent heavy selling is in the process of exhausting itself, and begin to look for entry point opportunities on the buy side. Looking at a chart of one year performance (below), SQQQ's low point in its 52 week range is $14.38 per share, with $43.71 as the 52 week high point — that compares with a last trade of $14.47. Proshares UltraPro Short QQQ shares are currently trading down about 0.8% on the day.