Later, Samuelson put this way: "If one could be sure that a price will rise, it would have already risen." (1965b, p. 41) If it is known that the price of a stock will go up tomorrow, it would already have gone up today, for who would sell it today without taking into account tomorrow's rise? Thus, Kendall's results could indicate that "speculation is doing its best because it leaves everybody with white noise" in other words, with randomness (Samuelson interview).

Donald MacKenzie, An Engine, Not a Camera, loc. 279