In trading on Friday, shares of the iShares Morningstar Mid-Cap Value ETF (JKI) entered into oversold territory, changing hands as low as $119.77 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 iShares Morningstar Mid-Cap Value, the RSI reading has hit 29.7 — by comparison, the RSI reading for the S&P 500 is currently 34.3. A bullish investor could look at JKI's 29.7 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), JKI's low point in its 52 week range is $100.58 per share, with $125.69 as the 52 week high point — that compares with a last trade of $120.01. iShares Morningstar Mid-Cap Value shares are currently trading off about 0.2% on the day.