In trading on Friday, shares of the Proshares Ultra Silver ETF ( AGQ) entered into oversold territory, changing hands as low as $61.03 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 Proshares Ultra Silver, the RSI reading has hit 29.4 — by comparison, the RSI reading for the S&P 500 is currently 54.9. A bullish investor could look at AGQ's 29.4 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), AGQ's low point in its 52 week range is $56.25 per share, with $106.08 as the 52 week high point — that compares with a last trade of $61.09. Proshares Ultra Silver shares are currently trading off about 3.6% on the day.