That's the age old question. On bottom fishing expeditions such as BK and the like you can throw out most technical indicators. Most every TA tool I look at is massively oversold. The caution here is: Oversold can become MORE oversold.
I want to see some indication that the selling has stopped (capitulation) or at least paused, and for that I defer to the faithful Japansese candlestick. A hammer bottom would be most appropriate with a doji coming in close second.