A sustainable breakout occurs when price moves decisively above a key resistance level and is able to hold above it for some time, indicating genuine buying strength rather than a temporary spike. Such breakouts are usually supported by strong volume, solid candle closes above resistance, and follow-through buying in subsequent sessions. When the breakout level turns into support on minor pullbacks, it confirms market acceptance at higher prices. This behavior suggests that demand is in control and increases the probability of a continued upward trend instead of a false breakout.