A Fibonacci trading tool used to aid investors in indentifying price movements. Essentially, using this model, investors attempt to buy high and sell low. One of its main uses is to indentify the underlying structures of price movements by analyzing the changing shape of the ellipse. The Phi Ellipse is normally drawn by a computer program due to its complexity.

Generally speaking, a phi ellipses is used to detect price patterns so investors are better capable of forecasting pricing moves, and therefore, able to detect when a buy or sell is in order. These patterns found in the ellipses have practical application to many trading forums, such as Forex trading platforms.