In trading on Tuesday, shares of the iShares Global Utilities ETF ( JXI) entered into oversold territory, changing hands as low as $47.515 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 Utilities, the RSI reading has hit 28.8 — by comparison, the RSI reading for the S&P 500 is currently 38.8. A bullish investor could look at JXI's 28.8 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), JXI's low point in its 52 week range is $41.73 per share, with $51.18 as the 52 week high point — that compares with a last trade of $47.60. iShares Global Utilities shares are currently trading off about 0.5% on the day.