In trading on Thursday, shares of the Australian Dollar Trust ETF ( FXA) entered into oversold territory, changing hands as low as $91.07 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 Australian Dollar Trust, the RSI reading has hit 28.8 — by comparison, the RSI reading for the S&P 500 is currently 51.3. A bullish investor could look at FXA'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), FXA's low point in its 52 week range is $86.98 per share, with $97.41 as the 52 week high point — that compares with a last trade of $91.07. Australian Dollar Trust shares are currently trading down about 0.6% on the day.