In trading on Monday, shares of the BLDRS Asia 50 ADR Index Fund ETF (ADRA) entered into oversold territory, changing hands as low as $27.82 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 BLDRS Asia 50 ADR Index Fund, the RSI reading has hit 29.3 — by comparison, the RSI reading for the S&P 500 is currently 35.8. A bullish investor could look at ADRA's 29.3 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), ADRA's low point in its 52 week range is $26.57 per share, with $31.51 as the 52 week high point — that compares with a last trade of $27.82. BLDRS Asia 50 ADR Index Fund shares are currently trading off about 2.1% on the day.