https://en.wikipedia.org/wiki/A_Random_Walk_Down_Wall_Street
> The concept can be traced to French broker Jules Regnault who published a book in 1863 [0]
[0] https://en.wikipedia.org/wiki/Random_walk_hypothesis
It is a good read. And still relevant.
https://en.wikipedia.org/wiki/A_Random_Walk_Down_Wall_Street