Quant interview prep guides

Expected Value Betting Final Review

Expected value betting final review covering fair price, break-even probability, conditional updates, information value, sizing, stopping, and common mistakes.

Candidates finishing the expected-value and betting prep cluster.

Fair price and threshold

Start final review by checking that you can turn a payoff distribution into a fair price and a break-even probability.

Conditional updates

For prompts with revealed information, update probabilities before recomputing expected value. Do not mix prior and posterior quantities.

Information value

Information is worth paying for only when it changes the decision enough to beat its cost.

Sizing and utility

Positive expected value answers should still mention bankroll, utility, drawdown, and estimation error when the prompt includes risk constraints.

Stopping and sequence

For repeated or staged games, define the state, compare stop value with continuation value, and avoid assuming a stopping rule creates edge.

Final answer checklist

State assumptions, net payoffs, probabilities, expected value, decision threshold, and any caveat about uncertainty or risk before giving the final choice.

Practice the pattern

Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.