Greg Meadors - Gann's Law of Price Movement Applied to Today´s Market (tradesforaliving.com)
As a young stockbroker, W.D. Gann already suspected that there were unseen causes, operating behind the scenes that were responsible for price movements in stocks and commodities.
He liked to think that these hidden causes were part of a natural law that was secretly at work in the markets. As he acquired more knowledge and developed his theories, Gann systematized his theory of price movement and called it the "Law of Vibration". In the Ticker Magazine1 interview Gann states, "In going over the history of markets and the great mass of related statistics, it soon becomes apparent that certain laws govern the changes and variations in the value of stocks, and there exists a periodic or cyclic law which is at the back of all these movements. I soon began to note the periodical reoccurrence of the rise and fall of stocks and commodities. This led me to conclude that natural law was the basis of market movements.