Quant Interview Questions
A practical map of quant interview question types: probability, expected value, market making, mental math, estimation, statistics, and coding.
Students preparing for quant trading, research, developer, or internship interviews.
What quant interviews usually test
Most quant interviews test structured reasoning under uncertainty. Expect probability, expected value, combinatorics, statistics, market making games, estimation, mental arithmetic, and coding. A good answer states the model, explains the tradeoff, checks the result, and adapts when the interviewer changes an assumption.
Concrete example
A simple prompt like "roll two dice, what is the chance the max is at least five" tests counting and complements. The clean path is to count the opposite event: both dice are at most four, so 16 of 36 outcomes fail and 20 of 36 succeed.
How to practice
Practice by pattern, not by memorized puzzle. Put coin, dice, card, Bayes, expected value, market making, and estimation questions into separate buckets, then do mixed sets once the methods are stable. LeetQuidity calibration is useful when you need to find the bucket that is actually weak.
Common mistakes
Candidates often jump to formulas before defining the sample space, hide arithmetic, or keep solving after the interviewer has given a hint. In a real interview, visible reasoning beats silent speed. State what you are conditioning on and sanity-check the scale of every answer.
Practice the pattern
Use the LeetQuidity curriculum and calibration to turn this topic into a focused practice plan.