When a stock breaks out above an important resistance level, that previous resistance can often become a new support zone. This happens because buyers who missed the initial breakout may enter during a retest, while existing buyers defend the breakout level. A successful retest and bounce from the breakout point strengthens the validity of the breakout and can indicate continued bullish momentum. The higher the volume during the breakout, the more significant the level can become. However, if price falls decisively below the breakout zone and fails to reclaim it, the breakout may be considered failed.
In simple terms:
Resistance → Breakout → Retest → Previous resistance becomes support → Bounce = bullish continuation.