Citadel / Citadel Securities hires Quant Researcher, Quant Trader, Software Engineer and ML Engineer. Candidates report 6 interview stages depending on the track (8 distinct rounds across all tracks). Below: what each round tests and how to prepare, the path by track, the timeline, pay and a 4-week prep plan, drawn from candidate reports and Citadel's own recruiting pages.
Citadel interview: quick answer
- StagesBy track: Quant Researcher: 6 · Quant Trader: 6 · Software Engineer: 6 (8 distinct rounds across all tracks)
- Online assessment~70 min · HackerRank (SWE / quant-dev track)
- TimelineAbout 4 to 5 weeks, per Citadel Securities' published process
- Final roundTeam-Fit / Final Round: 45 min - with hiring team
- Pay (candidate-reported)Quant Researcher (Citadel hedge fund), PhD, first year: $400k – $800k (typ. $500–600k) total comp
- RolesQuant Researcher, Quant Trader, Software Engineer, ML Engineer
Preparing for Citadel? Work the rounds in order in the free Citadel interview funnel, or start with the free online-assessment sample (no signup).
The Citadel interview process at a glance
| # | Round | Format and length | Who takes it | Prep |
|---|---|---|---|---|
| 1 | Online Assessment | ~70 min · HackerRank (SWE / quant-dev track) | Software Engineer | OA guidePractice |
| 2 | First-Round Phone Screen | 45-60 min - video | All tracks | GuidePractice |
| 3 | Behavioral / Culture-Add Round | 30 min · with senior researcher | All tracks | GuidePractice |
| 4 | Trading / Market-Making Simulation | 45–60 min · interactive · trading & QT tracks | Quant Trader | GuidePractice |
| 5 | Super Day Quantitative Math | 60 min · whiteboard | All tracks | GuidePractice |
| 6 | Super Day Coding | 60 min · CoderPad (Python preferred) | All tracks | GuidePractice |
| 7 | Super Day ML / Statistics | 60 min · whiteboard | Quant Researcher | GuidePractice |
| 8 | Team-Fit / Final Round | 45 min - with hiring team | All tracks | GuidePractice |
Stages are listed in the order candidates report them. Formats come from candidate reports and change between cycles, offices and teams; the "Who takes it" column shows which track each round belongs to.
How the Citadel process differs by track
Citadel runs separate loops for different roles. Here is the path each track reports, in order:
- Quant Researcher (6 stages): First-Round Phone Screen → Behavioral / Culture-Add Round → Super Day Quantitative Math → Super Day Coding → Super Day ML / Statistics → Team-Fit / Final Round
- Quant Trader (6 stages): First-Round Phone Screen → Behavioral / Culture-Add Round → Trading / Market-Making Simulation → Super Day Quantitative Math → Super Day Coding → Team-Fit / Final Round
- Software Engineer (6 stages): Online Assessment → First-Round Phone Screen → Behavioral / Culture-Add Round → Super Day Quantitative Math → Super Day Coding → Team-Fit / Final Round
Not sure which track fits you? See quant trader vs quant researcher.
Every Citadel round: what it tests and how to prepare
1Online Assessment
Citadel's first filter cuts hard, by track. SWE / quant-dev: two coding problems on HackerRank in about 70 minutes, drawn from a large rotating pool (strict time, all tests must pass). Trading / QT: a shorter, probability-heavy test (reported as about 15 fill-in probability and statistics questions). Quant Research (QR): the published QR process lists no automated test; live coding happens in a CoderPad interview.
Question types: mostly coding, especially complexity analysis, data structures, dynamic programming and sorting and searching. Latest candidate report for this round: Jun 2026.
How to prepare
- Coding bar is leetcode-medium. Finish both; don't get stuck on optimal.
Citadel online assessment guide →Practice this round (12 questions) →
2First-Round Phone Screen
A 45-60 min remote interview blending technical and behavioural. Core technical: one coding question (LeetCode-medium, Python or C++) plus a probability/statistics question for quant tracks. Recruiter intro up front; they screen for correct, efficient code written quickly and for genuine interest in Citadel.
- A remote video interview on CoderPad: 45 to 60 minutes for quant research, 45 minutes for engineering. The link comes in advance, so test it.
- For quant research it covers programming, data structures and algorithms, and research ability, plus behavioural questions on internships, projects and why Citadel.
Question types: mostly expectation, coding and probability, especially conditional probability, complexity analysis, data structures and expected value. Latest candidate report for this round: Jun 2026.
How to prepare
- They share screen via CoderPad — get comfortable with that UI before the call.
- Their probability questions LOVE conditional expectation. Drill it.
Full First-Round Phone Screen guide →Practice this round (13 questions) →
3Behavioral / Culture-Add Round
Candidate-reported as a separate 30-minute round: 'Why Citadel' + 'tell me about a project' + 1 ethics/dilemma scenario. In the published QR and engineering processes, behavioural questions sit inside the first technical round, and engineering adds a leadership interview after the three technical interviews.
- In the published quant research and engineering processes, behavioural questions sit inside the first technical round, and engineering adds a leadership interview after the three technical interviews.
How to prepare
- Have a 3-bullet 'why systematic trading' answer ready.
- STAR format for project stories — situation, task, action, result.
Full Behavioral / Culture-Add Round guide →Practice this round →
4Trading / Market-Making Simulation
Trading/QT track: Citadel Securities runs live market-making simulations. Quote a two-sided market on an uncertain value as the interviewer trades against you; update quotes and inventory as flow reveals information. Scored on quote discipline, inventory awareness, and clear reasoning under pressure over exact numbers.
- Citadel Securities quant trading candidates describe the final round as weighted toward market making.
How to prepare
- Quote WIDE first, then tighten. Early on you don't know the value — over-tight quotes get picked off. Widen with uncertainty, narrow as flow reveals signal.
- Track inventory out loud. If you're long, skew your quote down; show them you see your position and are managing it, not re-quoting blindly.
- Price from EV, then add edge. State the fair value, quote a spread around it, and widen the spread for adverse selection.
Full Trading / Market-Making Simulation guide →Practice this round →
5Super Day Quantitative Math
Part of the all-day Super Day (a series of ~45-min interviews). Two or three probability/statistics problems back-to-back - expect full derivations, not just final answers.
- The quant research onsite is three to five interviews of about an hour each, covering probability derivations, coding and ML or statistics.
Question types: mostly expectation, probability and game theory, especially expected value, conditional probability, order statistics and symmetry. Latest candidate report for this round: Jun 2026.
How to prepare
- Derive, don't recall. They want the steps.
- Conditional expectation is the hammer. Most rounds reduce to first-step analysis or E[X] = E[E[X|Y]]. Make it reflexive.
- Sanity-check the answer. Limits, symmetry, and units. Catching your own error scores better than a lucky number.
Full Super Day Quantitative Math guide →Practice this round (23 questions) →
6Super Day Coding
C++/Python emphasis; correctness, edge cases, and complexity under time pressure.
- Engineering candidates do three 45-minute technical interviews after the CoderPad round.
Question types: mostly coding and time series, especially data structures, complexity analysis, sorting and searching and two pointers and sliding windows. Latest candidate report for this round: Jun 2026.
How to prepare
- The refactor part is graded as much on questions you ASK as code you write.
Full Super Day Coding guide →Practice this round (17 questions) →
7Super Day ML / Statistics
A Super Day round for QR/ML tracks: regression, model diagnostics, regularization. They probe assumptions hard - be ready to justify 'why does this hold.'
- ML and statistics are part of the three to five hour-long quant research onsite interviews.
Question types: mostly regression, time series and statistics, especially matrix operations, variance, regularization and convex optimization. Latest candidate report for this round: Jun 2026.
How to prepare
- Know OLS cold, then its assumptions. Be ready to state Gauss-Markov, derive β̂ = (XᵀX)⁻¹Xᵀy, and explain what breaks under heteroskedasticity / collinearity / endogeneity.
- Regularization with a reason. Ridge vs. lasso, the bias-variance trade-off, and how you'd pick λ (CV vs. MSE minimization) — they probe 'why does this hold' hard.
- Diagnose before you model. Residual plots, leverage, multiple-testing / overfitting traps. Show you'd validate out-of-sample, not just fit.
Full Super Day ML / Statistics guide →Practice this round (22 questions) →
8Team-Fit / Final Round
After the Super Day, hiring managers across Citadel and Citadel Securities review your feedback; teams that are interested run a final fit interview.
- Hiring managers review feedback across Citadel and Citadel Securities. You can state a team preference; placement depends on skills and business need.
- Engineering candidates have a leadership interview with a specific team before the final review.
How to prepare
- Think about why it would STOP working. Crowding, transaction costs, regime change. Senior interviewers push on robustness, not cleverness.
- It's a conversation. Bring questions about the desk and how research turns into live trading; treat it as a peer discussion, not a quiz.
Practice the Citadel rounds in order
Each round in the Citadel funnel has its own practice set, with worked solutions and progress tracking. A free account saves your progress across rounds.
Timeline
Citadel Securities' published guides put the quantitative research process at about four to five weeks, faster when a candidate has a competing deadline. The engineering process runs about eight weeks.
- Quant research: a remote CoderPad round, then an onsite of three to five interviews of about an hour, then a hiring-manager review.
- Engineering: a 45-minute CoderPad round, three 45-minute technical interviews, a leadership interview for a specific team, then a final review.
A 4-week Citadel prep plan
Built from the order of Citadel's rounds on the Quant Researcher path and the topics in each round's practice set. Compress it if your first interview is sooner. Other tracks can swap in their own rounds from the table above.
| When | Focus | What to do |
|---|---|---|
| Week 1 | Foundations | Review coding, expectation and regression, the topics that dominate Citadel's practice sets. Start with Quant coding course and Probability course. Work the easy and medium questions in the Citadel question set. |
| Week 2 | Early rounds: First-Round Phone Screen and Behavioral / Culture-Add Round | Practice expectation, coding and probability under time pressure, and take the free OA sample (format notes in the OA guide). Talk every answer through out loud; interviewers score the reasoning. |
| Week 3 | Later rounds: Super Day Quantitative Math, Super Day Coding, Super Day ML / Statistics and Team-Fit / Final Round | Move to regression, probability and time series. Do timed coding sessions in your interview language. Read how quant superdays work. |
| Week 4 | Rehearse the full loop | Run each practice round in order, redo the questions you missed, and prepare two project stories plus a specific answer to "why Citadel?" (see behavioral questions at trading firms). |
Citadel pay
| Role | Level | Total comp | Notes |
|---|---|---|---|
| Quant Researcher (Citadel hedge fund) | PhD, first year | $400k – $800k (typ. $500–600k) | Wide range, heavily PM-dependent. Most first-year hedge-fund QR offers concentrate around $350-500k. Strong PMs on hot pods can push first-year comp toward the upper band, and top performers in good years land far above this — multi-million-dollar first-years aren't unheard of but they're outliers, not the median. |
| Quant Researcher (Citadel Securities) | PhD, first year | $750k – $800k | Tighter band than the hedge fund. CitSec QR new-grad comp anchors around this range; the market-making side pays the standard top-of-market PhD package. |
| Quant Trader (Citadel Securities) | New grad | $500k – $600k | First-year baseline. Top desks pay more — heavily desk-dependent. |
| Software Engineer (either firm) | New grad (BS/MS) | $300k – $500k | Strong SWE comp, though traders/researchers usually paid more for equivalent tenure. |
| QR / QT — PM-track / top performer | 3–5 yrs (good year) | $1.5M – $5M+ | Top performers on the right pods can land far above the standard mid-level band. GQS is hardcore but pays accordingly. Comp is heavily performance-tied per-pod and varies year-to-year. |
Total compensation means base salary plus bonus and any sign-on, as candidates self-report it. Job postings usually show base salary only, so posted figures and outside salary pages often look lower. These are rough ranges, NOT offers or guarantees. Citadel pays at the top of the band in good years and PMs/top performers can blow past these numbers. Securities (CS) and hedge fund (Citadel) comp differ; figures below are blended. Source: Candidate self-reports aggregated from levels.fyi, Glassdoor, and community Discord — not employer-verified. Last updated May 22, 2026.
Full breakdown by level: Citadel salary guide.
Citadel teams and what their interviews test
Citadel (the hedge fund) runs as a multi-strategy platform: multiple semi-autonomous business units share infra but trade independently with their own P&L. Citadel Securities is a separate market-making firm with its own structure. Different interview funnels and often different recruiters across BUs; pick the one whose mandate matches your background.
| Business units | What it does | What its interviews test |
|---|---|---|
| Equities (incl. Surveyor, Ashler, Aptigon) PM / Senior QR | Citadel's long-short equity business — pod-based, with Surveyor / Ashler / Aptigon among the named platforms. Each PM runs an independent book inside its pod. | Equity factor reasoning, fundamental analysis, statistics. Pods often hire onto specific PM teams; signal-vs-noise discussions common. |
| Global Quantitative Strategies (GQS) Quant Researcher / ML Engineer | Pure systematic alpha. ML-heavy, alternative data, statistical arbitrage. The Citadel BU most similar to Two Sigma in research culture. | ML theory deep-dive, feature engineering, model diagnostics, the ML-stats onsite round. |
| Fixed Income & Macro Quant Researcher / Trader | Rates, FX, sovereign credit, macro. Larger discretionary + macro overlay than the equity-side BUs. | Stochastic processes, term-structure models, macro intuition. Less ML-flavored, more PDE-flavored math. |
| Commodities & Credit PM / Senior QR | Commodities trading and credit (corporate, securitized). Often discretionary-leaning with quant overlay. | Market-structure intuition + risk modeling. Less ML, more domain-aware reasoning. |
| Citadel Securities (separate firm) — Market Making Quant Trader / SWE | Equities + options + ETF + fixed-income market making. HFT-style. Separate company from the hedge fund — different interview, different mandate. | Mental math + microstructure + low-latency coding. Closer to HRT than to Citadel HF in interview style. |
About Citadel
| Firm type | Multi-strat hedge fund + Citadel Securities (MM) |
|---|---|
| Trading style | Mixed · Mixed — HFT (CS) to discretionary (fund) |
| Founded | 1990 |
| Headquarters | Miami, FL (moved from Chicago in 2022) |
| Other offices | Chicago, New York, NY, London, Hong Kong |
| AUM (hedge fund) | ~$66B (end-2024) |
| Employees | ~3,150 |
| Reported performance | Wellington +15.1% (2024) |
| Quant research timeline | About 4 to 5 weeks, per Citadel Securities' published process |
| Engineering timeline | About 8 weeks, per the published engineering process |
| First technical round | Remote CoderPad interview, 45 to 60 minutes for quant research and 45 minutes for engineering |
Founded 1990 by Ken Griffin
Citadel was founded in 1990 by Ken Griffin while he was still at Harvard. Grew into one of the most successful multi-strategy hedge funds in history. Citadel Securities (the market-making arm) was founded later (2002) and operates as a separate entity. Both are headquartered in Miami as of 2022, with significant presence in Chicago, NYC, London.
Ken Griffin's culture
Founder + CEO Ken Griffin is famously hands-on and famously demanding. Interviewers tend to mirror this — direct, fast-paced, and focused on whether you'll deliver under pressure. The flip side is that the firm pays at the very top of the market for people who do.
How the firm is positioned
Public coverage suggests Citadel's flagship Wellington fund has had multiple multi-billion-dollar profit years recently, consistently ranking among the most successful hedge funds of all time by absolute dollars made. Citadel Securities has reportedly captured material share of US retail-equity flow. Specific year-by-year numbers vary — don't quote them in interviews unless you can cite.
Tech stack
Python for research; C++ for low-latency paths (especially at Citadel Securities). Internal research platform is custom. ML pillars (QS) use the standard PyTorch / scikit / pandas stack. Across both firms, code-review culture is reportedly strong.
Culture
Performance-driven and intense — Ken Griffin's reputation for paying top dollar AND demanding top output is accurate. Strong segmentation across business units (pods). GQS specifically is known as the hardcore engineering-research culture within Citadel.
What the interviews feel like
Long, multi-round, business-unit-specific. The behavioral round is unusual in that it runs BEFORE the technical onsite, not after — Citadel screens cultural fit early.
Junior reality (esp. the Securities arm)
Can be a pipeline / pigeonhole shop: juniors often get locked to one narrow area, and there is real internal politics. Growth depends heavily on landing a good desk and manager, so know exactly where you are placed.
Practice for Citadel on QuantVault
Practice
Courses
Games and drills
Further reading
- How quant superdays work
- Market-making game interview guide
- Behavioral questions at trading firms
- C++ and low-latency interview questions
- The quant interview process, explained
Similar firms to compare
Firms with a similar business and interview style. Many candidates interview at several of them in the same cycle.
Sources and how this guide is built
- Updated October 20, 2026; firm data last reviewed May 22, 2026; pay last updated May 22, 2026.
- Round detail draws on 440 questions candidates report from Citadel interviews (the most recent report across all rounds is from Jul 2026). A separate curated Citadel question set of 97 problems collects the most useful practice for this firm.
- Public candidate reports and outside interview guides are cross-checked against each other. Where they disagree the page says "reports differ"; details from a single source are marked as candidate reports.
- No actual interview questions are reproduced on this page. The questions, with worked solutions, are in the practice rounds.
Citadel interview FAQ
How many rounds are in the Citadel interview?
It depends on the track: Quant Researcher: 6; Quant Trader: 6; Software Engineer: 6 stages. Across all tracks candidates report 8 distinct rounds: Online Assessment, First-Round Phone Screen, Behavioral / Culture-Add Round, Trading / Market-Making Simulation, Super Day Quantitative Math, Super Day Coding, Super Day ML / Statistics, Team-Fit / Final Round.
What happens in the Citadel final round?
Team-Fit / Final Round (45 min - with hiring team). After the Super Day, hiring managers across Citadel and Citadel Securities review your feedback; teams that are interested run a final fit interview.
Does the Citadel process differ by role?
Yes. Quant Researcher: First-Round Phone Screen, Behavioral / Culture-Add Round, Super Day Quantitative Math, Super Day Coding, Super Day ML / Statistics, Team-Fit / Final Round. Quant Trader: First-Round Phone Screen, Behavioral / Culture-Add Round, Trading / Market-Making Simulation, Super Day Quantitative Math, Super Day Coding, Team-Fit / Final Round. Software Engineer: Online Assessment, First-Round Phone Screen, Behavioral / Culture-Add Round, Super Day Quantitative Math, Super Day Coding, Team-Fit / Final Round.
How much does Citadel pay?
Candidate-reported total compensation: Quant Researcher (Citadel hedge fund) (PhD, first year) $400k – $800k (typ. $500–600k); Quant Researcher (Citadel Securities) (PhD, first year) $750k – $800k; Quant Trader (Citadel Securities) (New grad) $500k – $600k; Software Engineer (either firm) (New grad (BS/MS)) $300k – $500k. These are self-reported totals including bonus, not offers; job postings usually list base salary only.
How should I prepare for the Citadel interview?
Prepare round by round over about four weeks: foundations first, then the early rounds (Online Assessment, First-Round Phone Screen, Behavioral / Culture-Add Round), then the later rounds, then a full rehearsal. Each round has its own practice set on QuantVault, and the online assessment has a dedicated guide.
What does Citadel do?
Citadel / Citadel Securities is a multi-strat hedge fund + Citadel Securities firm headquartered in Miami, FL (moved from Chicago in 2022). Citadel was founded in 1990 by Ken Griffin while he was still at Harvard. Grew into one of the most successful multi-strategy hedge funds in history.
Are Citadel and Citadel Securities the same interview?
For quantitative research and engineering, the two firms run a joint process, and hiring managers across both firms review the same feedback.
Is there an online assessment for quant research?
The published quant research process lists no online test. It starts with a remote CoderPad interview.
Which programming languages can I use?
Citadel Securities names Python and C++ and says it welcomes any language.
How long does the process take?
About four to five weeks for quant research and about eight weeks for engineering, per the firm's published guides.
Do I choose my team?
You can state a preference. Placement depends on your skills and on business need, and feedback is reviewed across both firms.
Start preparing for Citadel
Open the interactive Citadel interview funnel: every stage with its practice set, from the first screen to the final round. Create a free account to save your progress.