What Is an ABCD Pattern? ... A visual, geometric price/time pattern comprised of 3 consecutive price swings, or trends—it looks like a lightning bolt on price chart. A leading indicator that helps determine where & when to enter and exit a trade.The pattern consists of three legs, with two equal legs labelled AB and CD, together they form a zig-zag shape. For this reason it is sometimes called the ' ...AB=CD is a reversal pattern that helps you identify when the price is about to change direction. The idea is that you can buy when prices are low and about to rise or sell when they are high but about to fall.