$MMTC A trendline breakout occurs when the price moves decisively above a downward trendline or below an upward trendline, indicating a potential change in the existing trend. A breakout above a resistance trendline suggests increasing buying momentum and may signal the start of an uptrend, while a breakout below a support trendline indicates growing selling pressure and a possible downtrend. Traders often look for strong volume and a candle close beyond the trendline to confirm the breakout and reduce the risk of false signals.