In trading on Friday, shares of the PowerShares DWA Healthcare Momentum Portfolio ETF ( PTH) entered into oversold territory, changing hands as low as $42.75 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 DWA Healthcare Momentum Portfolio, the RSI reading has hit 29.4 — by comparison, the RSI reading for the S&P 500 is currently 40.4. A bullish investor could look at PTH's 29.4 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), PTH's low point in its 52 week range is $37.84 per share, with $52.64 as the 52 week high point — that compares with a last trade of $42.84. PowerShares DWA Healthcare Momentum Portfolio shares are currently trading down about 2.9% on the day.