SPX vs IMF

[...] I have determined the major and minor time factors which repeat in the history of nations, men and markets [...] In making my predictions I use geometry and mathematics, just as the astronomer does, based on immutable laws.

[...] My calculations are based on the cycle theory and on mathematical sequences. History repeats itself. That is what I have always contended, that in order to know and predict the future of anything you only have to look up what has happened in the past and get a correct base or starting point.

[...] In making my calculations on the stock market, or any future event, I get the past history and find out what cycle we are in and then predict the curve for the future, which is a repetition of past market movements [...] harmonic analysis, is the only thing that we can rely upon to ascertain the future.

W.D. Gann (1927): The Tunnel Thru The Air