In trading on Thursday, shares of T-Mobile US Inc (Symbol: TMUS) entered into oversold territory, hitting an RSI reading of 29.3, after changing hands as low as $55.23 per share. By comparison, the current RSI reading of the S&P 500 ETF ( SPY ) is 51.9. A bullish investor could look at TMUS's 29.3 RSI reading today 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.