In trading on Monday, shares of the Proshares Ultra MSCI Japan ETF (EZJ) entered into oversold territory, changing hands as low as $70.1101 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 Proshares Ultra MSCI Japan, the RSI reading has hit 27.5 — by comparison, the RSI reading for the S&P 500 is currently 54.7. A bullish investor could look at EZJ's 27.5 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), EZJ's low point in its 52 week range is $46.55 per share, with $96.97 as the 52 week high point — that compares with a last trade of $70.61. Proshares Ultra MSCI Japan shares are currently trading down about 3.6% on the day.