In trading on Tuesday, shares of the China Infrastructure ETF ( CHXX) entered into oversold territory, changing hands as low as $16.75 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 China Infrastructure, the RSI reading has hit 29.99 — by comparison, the RSI reading for the S&P 500 is currently 39.8. A bullish investor could look at CHXX's 29.99 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), CHXX's low point in its 52 week range is $14.61 per share, with $19.94 as the 52 week high point — that compares with a last trade of $16.75. China Infrastructure shares are currently trading off about 0.6% on the day.