In trading on Thursday, shares of the First Trust US IPO Index Fund ETF ( FPX) entered into oversold territory, changing hands as low as $51.08 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 US IPO Index Fund, the RSI reading has hit 27.4 — by comparison, the RSI reading for the S&P 500 is currently 33.4. A bullish investor could look at FPX's 27.4 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), FPX's low point in its 52 week range is $42.23 per share, with $54.59 as the 52 week high point — that compares with a last trade of $51.10. First Trust US IPO Index Fund shares are currently trading off about 1% on the day.