In trading on Monday, shares of the Vanguard Short-Term Government Bond ETF ( VGSH) entered into oversold territory, changing hands as low as $60.85 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 Vanguard Short-Term Government Bond, the RSI reading has hit 27.9 — by comparison, the RSI reading for the S&P 500 is currently 60.4. A bullish investor could look at VGSH's 27.9 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), VGSH's low point in its 52 week range is $60.68 per share, with $61.44 as the 52 week high point — that compares with a last trade of $60.91. Vanguard Short-Term Government Bond shares are currently trading down about 0.1% on the day.