ACD is right of course, but Bachelier's contribution was somewhat forgotten for a while. The idea was re-introduced by Osborne in 1959:Osborne M.F.M. "Brownian Motion in the Stock Market." Operations Research, 10, 345-379 (1959).and after that was always part of the mainstream of Finance.
Last edited by acastaldo
on February 2nd, 2012, 11:00 pm, edited 1 time in total.