In trading on Friday, shares of the PowerShares International Dividend Achievers Portfolio ETF (PID) entered into oversold territory, changing hands as low as $13.71 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 International Dividend Achievers Portfolio, the RSI reading has hit 27.1 — by comparison, the RSI reading for the S&P 500 is currently 31.4. A bullish investor could look at PID's 27.1 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), PID's low point in its 52 week range is $11.08 per share, with $15.78 as the 52 week high point — that compares with a last trade of $13.74. PowerShares International Dividend Achievers Portfolio shares are currently trading off about 1% on the day.