In trading on Tuesday, shares of the DB Oil Fund ETF (DBO) entered into oversold territory, changing hands as low as $24.37 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 DB Oil Fund, the RSI reading has hit 29.6 — by comparison, the RSI reading for the S&P 500 is currently 54.6. A bullish investor could look at DBO's 29.6 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), DBO's low point in its 52 week range is $22.62 per share, with $30.65 as the 52 week high point — that compares with a last trade of $24.47. DB Oil Fund shares are currently trading off about 0.2% on the day.