In trading on Wednesday, shares of the ETFS Physical Silver Shares ETF (SIVR) entered into oversold territory, changing hands as low as $22.27 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 ETFS Physical Silver Shares, the RSI reading has hit 28.0 — by comparison, the RSI reading for the S&P 500 is currently 70.6. A bullish investor could look at SIVR's 28.0 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), SIVR's low point in its 52 week range is $22.27 per share, with $34.85 as the 52 week high point — that compares with a last trade of $22.41. ETFS Physical Silver Shares shares are currently trading down about 3.5% on the day.