Quant interview prep guides

Expected Value Under Uncertainty Interview Questions

Expected value under uncertainty interview guide for scenario weighting, uncertain inputs, robustness, and assumption-first answers.

Candidates who can compute expected value but struggle when probabilities or payoffs are estimates.

Separate two kinds of uncertainty

Outcome uncertainty is the randomness of the event itself. Parameter uncertainty is not knowing the exact probability, payoff, or cost that belongs in the expected value calculation.

Use scenarios when inputs are fuzzy

If a prompt gives a range of probabilities or payoffs, compute expected value under a few plausible scenarios instead of pretending one estimate is exact.

Concrete example

If a project pays 10 on success but the success probability might be 30, 40, or 50 percent, the expected gross payoff ranges from 3 to 5 before cost.

Discuss robustness

A decision is more robust when it remains positive expected value across reasonable assumptions. A decision that only works under the most optimistic input deserves caution.

State what would change your answer

Good interview answers name the missing input that matters most, such as the true probability, downside size, or cost of capital.

Common mistakes

Candidates often present a precise number from imprecise assumptions. It is usually stronger to give the calculation and the sensitivity around it.

Practice the pattern

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