In trading on Monday, shares of the Indonesia Index ETF ( IDX) entered into oversold territory, changing hands as low as $23.20 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 Indonesia Index, the RSI reading has hit 25.9 — by comparison, the RSI reading for the S&P 500 is currently 39.5. A bullish investor could look at IDX's 25.9 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), IDX's low point in its 52 week range is $20.06 per share, with $27.70 as the 52 week high point — that compares with a last trade of $23.26. Indonesia Index shares are currently trading off about 3.2% on the day.