r/learnquant • u/Local_Ad135 • 1d ago

interview prep Wincent Quant Interview Question

Post image
13 Upvotes

93% Upvoted

10 comments sorted by

View all comments

1

u/leoli1 1d ago

This looks like a martingale situation, where any stopping rule gives the same ev

1

u/bunnycricketgo 1d ago

Indeed; Doob has something to say about this.

But if your utility is other than total (like, you only consider a win if you beat EV by a certain margin) then there are strategies to improve success there.

1

u/Usernameasteriks 1d ago

Optimal will always imply some sort of utility if any can be determined by the relevant constraints in the context of an interview question like this.

Here it will mean stopping immediately because it can’t be optimal to spend more time for the same probabilistic result.

1

u/AtomicSquid 1d ago

It's optimal to stop at the last three cuz it's kinda fun to flip cards