W.D. Gann made his fortune using methods that he developed for trading instruments based on relationships between price movement and time, known as time/price equivalents.

Fibonacci numbers: The Fibonacci number sequence (1, 1, 2, 3, 5, 8, 13, 21, 34 ...) is constructed by adding the first two numbers to arrive at the third.

Government budget deficits or surpluses: The market usually reacts negatively to widening government budget deficits, and positively to narrowing budget deficits. The impact is reflected in the value of a country's currency.