Traders in that third group are a mixed bunch. But a lack of conviction has kept them out of the market thus far. They have no vested interest in the market. It's already in the market. They do not move haphazardly.
History repeats itself.
Technicians believe anything that can affect the price of a commodity, be it fundamental, political, psychological or otherwise, will or has been reflected in price action before. And by studying how prices reacted under similar circumstances in the past, they believe they can forecast with reasonable accuracy how prices will react again.