In trading on Tuesday, shares of the Daily Gold Miners Bull 3x Shares ETF (NUGT) entered into oversold territory, changing hands as low as $10.83 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 Daily Gold Miners Bull 3x Shares, the RSI reading has hit 30.0 — by comparison, the RSI reading for the S&P 500 is currently 66.6. A bullish investor could look at NUGT's 30.0 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), NUGT's low point in its 52 week range is $9.61 per share, with $97.05 as the 52 week high point — that compares with a last trade of $11.02. Daily Gold Miners Bull 3x Shares shares are currently trading off about 9% on the day.