The Elliot Wave Theory is named after Ralph Nelson Elliott.
He concluded the movement of the stock market could be predicted by observing and identifying a repetitive pattern of waves, and these market movements (waves) are based on crowd behavior, which is seen as predictable given similar situations (ever notice how, with two left-turn lanes available and no particular reason to pick one or the other, most people line up in one lane, where others are lining up? Like that.)
Some Elliot Wave resources