In trading on Monday, shares of the iBonds Mar 2018 Corporate ETF (IBDB) entered into oversold territory, changing hands as low as $102.426 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 iBonds Mar 2018 Corporate, the RSI reading has hit 24.8 — by comparison, the RSI reading for the S&P 500 is currently 50.0. A bullish investor could look at IBDB's 24.8 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), IBDB's low point in its 52 week range is $100.98 per share, with $106.56 as the 52 week high point — that compares with a last trade of $102.43. iBonds Mar 2018 Corporate shares are currently trading off about 0.3% on the day.