In trading on Thursday, shares of the iShares Global REIT ETF (REET) entered into oversold territory, changing hands as low as $24.1901 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 Global REIT, the RSI reading has hit 27.3 — by comparison, the RSI reading for the S&P 500 is currently 59.2. A bullish investor could look at REET's 27.3 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), REET's low point in its 52 week range is $22.85 per share, with $28.84 as the 52 week high point — that compares with a last trade of $24.35. iShares Global REIT shares are currently trading down about 2.4% on the day.