There is a sense in which the efficient-market hypothesis and its predecessor, the random-walk hypothesis, always co-existed with contrary evidence. Holbrook Working, for example, believed it was possible to find at least some structure in the apparently random fluctuations of stock prices (Working 1958). So did another early formulator of the random-walk hypothesis: Alfred Cowles III, founder (and funder) of the Cowles Commission.

Donald MacKenzie, An Engine, Not a Camera, loc. 416