Oct 08, 2026 by Offer

Citadel Market Making Game 2027: How to Quote Tight

The Citadel market making game — commonly reported by candidates as "Play a market-making game: quote a bid and ask on an unknown quantity" — is won with three principles: center your quotes on your best estimate of fair value, keep the spread tight but wide enough to cover adverse selection, and update aggressively on every trade.

What This Citadel Market Making Game Assesses

Market making is Citadel's core business, so this game tests the instincts directly: pricing under uncertainty, managing the risk of trading with better-informed counterparties, and updating beliefs from order flow. Candidates who quote wide "to be safe" show they don't understand that a market maker who never trades earns nothing.

How to Answer This Citadel Market Making Game Question

Play it as a professional would:

Step 1 — Estimate fair value. Start from everything you know: prior information, base rates, any signals given. Your mid-price should be your honest best estimate. Example line: "With no information, my prior centers on the middle of the plausible range — I'll quote around that."
Step 2 — Set the spread. Quote bid below and ask above your estimate. The spread compensates for adverse selection — the risk that whoever trades with you knows more. Start moderately wide, then tighten as you learn; a spread that never gets hit teaches you nothing.
Step 3 — Update on flow. Every trade is information. If someone lifts your ask repeatedly, your estimate was low — move the mid up. If flow is balanced, tighten the spread and earn the edge. Narrate each update aloud: "Bought from twice — raising my mid."

The key insight to voice: your quotes are both prices and probes — each quote teaches you something about the true value.

Common Mistakes

Quoting too wide. A spread nobody trades is a forfeit — you learn nothing and earn nothing. Tighten until you get flow.
Never updating. Keeping the same quotes after being bought repeatedly shows you're ignoring the most valuable signal in the game.
No inventory awareness. If you accumulate a large position, shade quotes to flatten it — a market maker with a huge one-sided book isn't making markets, they're speculating.

Candidates commonly report that the interviewer plays adversarially — probing your quotes to find stale prices. Expect it: the game is designed so that static quotes get picked off, which is exactly why continuous updating is the skill being tested.

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FAQ

How tight should my first spread be? Tight enough to get traded, wide enough to survive being wrong. Start moderate and let the flow tell you — the first quotes are reconnaissance.

What if I have no idea of the value? Center on the middle of the stated range with a wider spread, then update fast. Admitting ignorance and pricing it in beats false confidence.

Should I ever refuse to quote? In the game, no — trade the flow. In real markets, widening aggressively is the equivalent; outright refusal is rarely the professional move.

How is this scored? On your P&L at the end, but mostly on your process: updating, spread discipline, and whether you articulate the adverse-selection logic.

Preparing for Citadel's interview? Our 2027 Citadel Online Assessment and Coding Challenge Tutorials has practice questions and answers — $79 one-time, instant download.