Quant interview prep guides

Mental Math Cluster Review Checklist

Mental math cluster review checklist for arithmetic, probability math, EV math, market-making math, Fermi estimation, and next drills.

Candidates finishing a mental math prep cycle.

Arithmetic checklist

Confirm that fractions, percentages, multiplication, division, square roots, and weighted averages are reliable before adding harder contexts.

Probability and EV checklist

Check that arithmetic supports the model: sample spaces, denominators, probability weights, net payoffs, and thresholds should be explicit.

Market-making checklist

Review midpoint, spread, percentage spread, probability price, inventory, and simple PnL calculations inside quote-based drills.

Fermi checklist

State the target, decompose drivers, use ranges, check units, sanity-check scale, and identify the dominant assumption before presenting the final estimate.

Common mistakes

Candidates often finish a cluster without retesting. Use the checklist to choose the next two drills, not just to mark topics complete.

Practice the pattern

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