In trading on Thursday, shares of the SPDR S&P International Telecommunications Sector ETF ( IST) entered into oversold territory, changing hands as low as $25.85 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 SPDR S&P International Telecommunications Sector, the RSI reading has hit 27.7 — by comparison, the RSI reading for the S&P 500 is currently 32.2. A bullish investor could look at IST's 27.7 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), IST's low point in its 52 week range is $24.00 per share, with $29.95 as the 52 week high point — that compares with a last trade of $25.85. SPDR S&P International Telecommunications Sector shares are currently trading off about 1.3% on the day.