Stock is in bear market for many years. It formed a double bottom pattern, gave breakout with volumes & now there is a strong pullback.
Double bottom is trend reversal pattern preceded by down move. After pattern breakout trend reverses to up-move. Location of pattern is important, such patterns workout superbly when such pattern is formed at long-term supports or a strong support.
In Case of NSE:BHEL Double bottom pattern is formed at multi year supports check below.