A trendline breakout Motilal Oswal Financial Services LimitedNSE:MOTILALOFSSandip_Tanaji_PatilA trendline breakout occurs when an asset's price crosses and closes outside a established diagonal trendline, signaling a potential trend reversal or continuation. Valid breakouts are confirmed by a strong candle close beyond the line, often accompanied by high volume, and sometimes a retest of the broken trendline.