A trendline breakout is a powerful technical concept where the price breaks through an established trendline — either support or resistance — signaling a potential trend reversal or continuation. When the price breaks above a downward trendline (resistance), it indicates that selling pressure is weakening and buyers are gaining control, giving a bullish signal. Conversely, when the price breaks below an upward trendline (support), it shows increasing selling pressure, giving a bearish signal. Traders usually confirm breakouts by checking for higher volume, candle closing beyond the trendline, and sometimes a retest of the breakout level to avoid false breakouts.