In trading on Wednesday, shares of the PowerShares Variable Rate Preferred Portfolio ETF ( VRP) entered into oversold territory, changing hands as low as $24.30 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 Variable Rate Preferred Portfolio, the RSI reading has hit 27.2 — by comparison, the RSI reading for the S&P 500 is currently 32.8. A bullish investor could look at VRP's 27.2 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), VRP's low point in its 52 week range is $24.30 per share, with $26.74 as the 52 week high point — that compares with a last trade of $24.33. PowerShares Variable Rate Preferred Portfolio shares are currently trading off about 0.4% on the day.