Levy once told J L Doob that "reading other writers' mathematics gave him physical pain" (see website below) so perhaps it was the case that Levy had never read Bachelier.
Magpataw ng buwis kapag sinasabi JL Doob na "pagbabasa ng iba pang mga writers' matematika ibinigay sa kanya ng pisikal na sakit" (tingnan ang website sa ibaba) kaya marahil ito ay ang kaso na pagpapataw ng buwis ay hindi kailanman read Bachelier.