In trading on Monday, shares of the Proshares Ultra Dow30 ETF ( DDM) entered into oversold territory, changing hands as low as $99.0101 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 Ultra Dow30, the RSI reading has hit 29.9 — by comparison, the RSI reading for the S&P 500 is currently 33.7. A bullish investor could look at DDM's 29.9 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), DDM's low point in its 52 week range is $78.50 per share, with $115.25 as the 52 week high point — that compares with a last trade of $99.46. Proshares Ultra Dow30 shares are currently trading off about 3.8% on the day.