In trading on Friday, shares of the PowerShares DB Energy Fund ETF ( DBE) entered into oversold territory, changing hands as low as $27.44 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 PowerShares DB Energy Fund, the RSI reading has hit 29.2 — by comparison, the RSI reading for the S&P 500 is currently 52.5. A bullish investor could look at DBE's 29.2 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), DBE's low point in its 52 week range is $27.28 per share, with $31.26 as the 52 week high point — that compares with a last trade of $27.41. PowerShares DB Energy Fund shares are currently trading off about 0.5% on the day.