The Wyckoff Methodology in Depth notes

Wyckoff and the first readers of the tape understood that the movements of the price do not develop in periods of time of equal duration, but that they do it in waves of different sizes, for this reason they studied the relation between the upward and downward waves. The price does not move between two points in a straight line; it does so in a wave pattern. At first glance they seem to be random movements, but this is not the case at all. The price is shifted up and down by fluctuations....

Wyckoff and the first readers of the tape understood that the movements of the price do not develop in periods of time of equal duration, but that they do it in waves of different sizes, for this reason they studied the relation between the upward and downward waves. The price does not move between two points in a straight line; it does so in a wave pattern. At first glance they seem to be random movements, but this is not the case at all. The price is shifted up and down by fluctuations....