In trading on Tuesday, shares of the First Trust STOXX European Select Dividend Index Fund ETF (FDD) entered into oversold territory, changing hands as low as $13.45 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 First Trust STOXX European Select Dividend Index Fund, the RSI reading has hit 29.9 — by comparison, the RSI reading for the S&P 500 is currently 48.3. A bullish investor could look at FDD's 29.9 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), FDD's low point in its 52 week range is $12.86 per share, with $15.63 as the 52 week high point — that compares with a last trade of $13.50. First Trust STOXX European Select Dividend Index Fund shares are currently trading off about 0.1% on the day.