In trading on Monday, shares of the iShares Japan Large-Cap ETF ( ITF) entered into oversold territory, changing hands as low as $48.25 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 Japan Large-Cap, the RSI reading has hit 27.7 — by comparison, the RSI reading for the S&P 500 is currently 38.0. A bullish investor could look at ITF's 27.7 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), ITF's low point in its 52 week range is $43.04 per share, with $53.67 as the 52 week high point — that compares with a last trade of $48.25. iShares Japan Large-Cap shares are currently trading down about 1.8% on the day.