Quant interview prep guides

Optimal Bet Sizing Interview Questions

Optimal bet sizing interview prep for edge, risk constraints, fractional sizing, Kelly intuition, and all-in mistakes.

Candidates practicing decision-making beyond simple expected value.

Sizing is a second decision

After deciding a toy bet has positive expected value, the next question may be how much to risk.

All-in is rarely the model answer

A favorable expected value does not automatically justify risking everything. Downside, repeatability, and utility matter.

Concrete example

A small positive edge repeated many times may support fractional sizing in a model, while a single large downside bet may not.

Kelly connection

Kelly-style reasoning links edge, odds, and bankroll fraction under log-growth assumptions. Those assumptions should be stated.

Constraints

Interview prompts may include maximum loss, limited bankroll, or position limits. Those constraints change the sizing answer.

Common mistakes

Candidates often stop at positive expected value. Sizing asks how much exposure is reasonable under the model.

Practice the pattern

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