Gann angles
The Gann Angles are named after W. D. Gann, a 20th-century market theorist. Gann described the use of the angles in the stock market in The Basis of My Forecasting Method, a 33-page course written in 1935. The legitimacy of Gann's techniques has been seriously questioned. Calculating a Gann angle is equivalent to finding the derivative of a particular line on a chart in a simple way.