Market Microstructure Interview Practice

Reviewed by Fallon Han· Updated 2026-05-22 18:50:08.416

This conversation was generated using Cook'd AI's career assistant and reviewed by Fallon Han from our editorial team for accuracy.

I am a second-year stats student in France and I want to practice market microstructure questions for market-making roles. Can you quiz me on liquidity, spreads, order books, and risk-taking behavior, then tell me if my answers are clear enough?

Absolutely. I will keep it close to a real finance interview and focus on precision. Question 1: If a stock suddenly becomes much more liquid, what usually happens to the bid-ask spread and why? Please answer in 2 to 4 sentences as if you were in an interview.

If liquidity increases, the bid-ask spread usually narrows because there are more buyers and sellers, so it is easier to trade without moving the price too much. Market makers face less adverse selection and inventory risk, so they can quote tighter prices.

Good answer. Clear and directionally correct. What you did well: - You linked higher liquidity to a narrower spread - You mentioned adverse selection and inventory risk, which is strong for a market-making role How to improve: - Say explicitly that tighter spreads reflect lower trading costs - Add one short example, such as higher volume after news or during peak hours Interview-grade version: 'When liquidity rises, bid-ask spreads usually narrow because there are more active counterparties and lower execution risk. For market makers, that reduces both adverse selection and inventory risk, so they can quote tighter prices and still expect to manage flow efficiently.' Question 2: What information can you infer from a deep order book versus a thin order book?

A deep order book means there are many limit orders close to the current price, so large trades can be absorbed with less price impact. A thin order book means there is less visible depth, so even moderate market orders can move the price more.

Strong answer. Concise and precise. Why it works: - You defined depth correctly - You connected depth to price impact, which is exactly the right intuition Minor upgrade: - Mention that a deep book can sometimes signal better short-term liquidity, but not necessarily true underlying value Question 3: Why might a market maker widen spreads during periods of high uncertainty?

Because uncertainty increases the chance of being picked off by better-informed traders. The market maker also faces more inventory risk, so widening spreads compensates for that extra risk and protects capital.

Very good. This is the right risk-taking logic for a market-maker interview. Assessment: - Clear explanation of adverse selection - Correct link to inventory risk - Good focus on compensation for risk To sound even sharper, say 'volatility and uncertainty' instead of only uncertainty, because interviewers often want the link to fast price moves. Polished answer: 'In periods of higher volatility or uncertainty, a market maker may widen spreads because the probability of adverse selection rises. If prices can move quickly, the dealer is more exposed to inventory losses, so wider spreads help compensate for that increased risk.' Final question: If you were given a choice between providing liquidity and taking liquidity, how would you explain when a market maker prefers one over the other?

A market maker usually prefers providing liquidity by posting limit orders when it wants to earn the spread and has enough confidence in its price estimate. It may take liquidity with market orders when it needs to reduce inventory quickly or hedge risk before prices move against it.

Excellent. That is a realistic market-making answer. Overall evaluation report: - Clarity: 9/10 - Precision: 9/10 - Microstructure understanding: 9/10 - Interview realism: 8.5/10 Strengths: - You used the correct market-making vocabulary - Your answers consistently tied mechanics to risk - You showed the trade-off between spread capture and inventory control What to refine next: - Give slightly more structure in every answer: definition, mechanism, implication - Add one concrete example where possible - Avoid vague phrases like 'move against it' without naming price movement or inventory exposure Best overall takeaway: You sound ready for a first-round market microstructure screen. With a bit more structure and one or two examples per answer, your responses would feel very polished.