dj... you can see oversold through some of the indicators on a chart
specifically the williams (wm%R) under -80, and the rsi's 14 and 6 under 30. you can also see how the stochastics shows the strength of the selling.
btw.... this looks to be at the beginning of a turn. it's also a ppo/adx pincher and when those turn up and play out they often (but not always) have big gains.
I use Quote Tracker..Trade with Interactive Brokers...I don't scan for oversold stocks...I have a watch list created after extensive DD...then I set alerts and watch for bottom on pullback...based on techicals ...one being RSI..hope this helps