There is no single best quant interview prep platform, and anyone who tells you otherwise is selling something. Quant interviews are a multi-stage funnel, and the tools that win you the mental-math round are not the ones that win you the coding round. The candidates who get offers almost always stitch together two or three resources rather than betting everything on one. This guide lays out the funnel, maps the well-known tools to the stages they actually serve, and says plainly where each is strong and where it is not, including where QuantVault fits.
How to think about quant interview prep
A typical quant trading or research pipeline runs in stages, and each stage rewards a different kind of practice:
- Online assessment (OA) — a timed first filter. Often HackerRank-style coding, a probability/stats quiz, or a data task. Firm-specific and time-pressured.
- Mental math / market-making — rapid arithmetic under a clock (the Zetamac-style 80-in-2-minutes filter) and making two-sided markets.
- Probability and brainteasers — expected value, conditional probability, combinatorics, and the classic puzzles, reasoned out loud.
- Coding — algorithms and, for some firms, a data-analysis or implementation task graded on correctness.
- Firm-specific rounds — super-days, trading games, and behavioral fit that vary firm to firm.
Match the tool to the stage you are weakest at, not to whatever is most popular. A drill app that fixes your arithmetic does nothing for your dynamic-programming gap, and a vast problem bank will not on its own get your hands fast enough for a two-minute speed test.
The tools, by job
Here is the honest rundown, grouped by what each tool is genuinely good for. No tool below is bad; they simply serve different stages.
| Tool | Type | Best for (stage) | Honest take |
|---|---|---|---|
| Zetamac | Mental-math drill | Mental math | The free default speed drill. A configurable timed arithmetic test that mirrors the classic 2-minute filter. Bare-bones and not trading-flavored, but the standard everyone trains on. Hard to beat for raw arithmetic speed. |
| TraderMath | Mental-math drill | Mental math (trading-realistic) | Drills built to feel like trading: prices, P&L, fractions, and decimal conversions, with progression. Closer to the desk than Zetamac; a good second drill once raw speed is there. |
| Brainstellar | Free puzzle bank | Probability / brainteasers | A free, well-loved set of probability and brainteaser puzzles with answers. Great for breadth and a daily puzzle habit; not structured into a curriculum or progress tracking. |
| QuantQuestions | Question bank | Probability, brainteasers, firm playlists | A curated question bank with firm-tagged playlists. Strong, hand-picked coverage; smaller and more editorial than an exhaustive bank. |
| QuantVault | Question bank + platform | Whole funnel (structured practice) | A large structured bank (2,800+ problems, full solutions) with firm-by-firm funnels, real OA tests, an auto-graded coding judge, courses, and trading games. Broad and structured; you still want a dedicated speed drill alongside it. |
| getcracked | Community / intel | Firm-specific rounds | A Discord community with recent interview reports and intel. Invaluable for knowing what a firm is asking right now; it is a community, not a practice bank. |
| The books | Reference texts | Method & canon | The Green Book, Heard on the Street, and Joshi's Quant Job Interview Questions teach the canonical methods. Essential for understanding, but static: no grading, no spacing, no firm-specific layer. |
Mental math: Zetamac and TraderMath
Speed is a hard filter at market-making firms, and it is trainable. Zetamac is the free default: a configurable timed arithmetic test that almost everyone uses to chase the classic 2-minute score. It is plain and not trading-specific, but it builds the raw speed the filter measures. TraderMath layers on trading realism — prices, fractions, decimal conversions, and P&L-style problems with progression — so it is the natural second drill once your raw arithmetic is fast. Many candidates run Zetamac daily and add TraderMath closer to interviews. For a deeper look, see our QuantVault vs TraderMath comparison.
Free puzzles: Brainstellar
Brainstellar is the go-to free puzzle bank for probability and brainteasers, with clean answers and good breadth. It is excellent for building a daily puzzle habit and seeing the classic families, and it costs nothing. What it does not do is structure those puzzles into a learning path, track what you have mastered, or grade you — it is a list, and a good one.
Question banks: QuantQuestions and QuantVault
QuantQuestions offers a curated bank with firm-tagged playlists; its strength is editorial selection — a tighter, hand-picked set rather than an exhaustive one. QuantVault sits at the other end: a large, structured bank with full worked solutions, firm funnels, an auto-graded coding judge, and progress tracking. Neither is strictly better; a curated set is faster to get through, a large bank gives more reps and coverage. We compare them directly in QuantVault vs QuantQuestions.
Community and intel: getcracked
Knowing what a firm is asking this season is its own edge, and that lives in communities, not banks. getcracked is a Discord with recent interview reports and candidate intel — the kind of fresh, firm-specific signal a static resource cannot provide. Treat it as your intel layer, paired with a bank for the actual reps. See QuantVault vs getcracked for how the two complement each other.
Books: the canonical texts
The books teach the methods everything else assumes. A Practical Guide to Quantitative Finance Interviews (the Green Book) is the default first read; Heard on the Street is the broadest brainteaser set; Quant Job Interview Questions and Answers by Mark Joshi is the targeted text for developer and pricing-desk roles. They are the canon — and they are static, with no grading, spacing, or firm layer. Read for method, then drill for recall. Our best quant interview books guide covers which to pick for which role.
Where QuantVault fits, honestly
QuantVault is built for one job: structured, large-volume practice across the whole funnel. That means a bank of 2,800+ problems with full worked solutions, intuition, and hints (396 free to start), firm-by-firm interview funnels with real OA tests, an auto-graded coding judge that runs your code in the browser like LeetCode, plus courses and interactive trading games for the market-making rounds. If your gap is "I need a lot of varied, graded reps with solutions I can learn from, organized by firm," that is exactly what it is for.
It is not the best tool at everything, and we will not pretend otherwise. For pure arithmetic speed, a dedicated drill like Zetamac is the right tool, and we recommend running one alongside QuantVault. For real-time, firm-specific intel, a Discord like getcracked beats any bank. The honest recommendation is to combine: a speed drill for mental math, a structured bank like QuantVault for problems, firm funnels, and coding, and a community for current intel. Start with the problem bank, browse a firm funnel such as Jane Street, and add the courses under Learn where a topic is shaky.
A sample plan: prep in N weeks
If you have roughly six to eight weeks, a workable structure is:
- Weeks 1–2 — foundations. 10–15 minutes of Zetamac daily to lock in speed; read the Green Book's probability and brainteaser chapters for method; drill the matching problem families on QuantVault to convert reading into recall.
- Weeks 3–4 — depth and breadth. Keep the daily drill; push probability and combinatorics volume; work coding problems through the auto-graded judge; add TraderMath for trading-flavored arithmetic.
- Weeks 5–6 — firm-specific. Pick your target firms and work their funnels and real OA tests end to end; play the trading games for market-making rounds; join a community like getcracked to learn each firm's current questions.
- Final week — sharpen. Timed mock OAs, daily speed drills, and a review pass over every problem you missed. Recognition fades; re-solve, do not re-read.
Compress or stretch this to your timeline, but keep the shape: a daily speed habit, a bank for the bulk of reps, firm funnels near the end, and a community for intel. No single tool covers all four — the stack does.
Frequently asked questions
What is the best quant interview prep platform in 2026?
There is no single best platform, because quant interviews are a multi-stage funnel. For raw mental-math speed, Zetamac is the free default (with TraderMath for trading-realistic drills). For free puzzles, Brainstellar. For a large, structured problem bank with full solutions, firm funnels, an auto-graded coding judge, and trading games, QuantVault. For current firm intel, a Discord like getcracked. Most successful candidates combine a speed drill, a question bank, and a community rather than relying on one tool.
How should I prepare for quant trading interviews?
Prep by stage, not by tool. The funnel runs OA, then mental math and market-making, then probability and brainteasers, then coding, then firm-specific rounds. Build daily arithmetic speed (Zetamac), drill a large structured problem bank with worked solutions (QuantVault), read the canonical books for method (the Green Book and Heard on the Street), work firm funnels and real OA tests near the end, and use a community for current interview intel. Re-solve missed problems rather than re-reading them, since recognition fades under pressure.
Is Zetamac or QuantVault better for quant prep?
They do different jobs and are best used together. Zetamac is a free, focused mental-math speed drill that trains the raw arithmetic the 2-minute filter tests. QuantVault is a structured practice platform: 2,800+ problems with full solutions (396 free), firm-by-firm funnels, real OA tests, an auto-graded coding judge, courses, and trading games. Use Zetamac daily for speed and QuantVault for the bulk of your problem reps, coding, and firm-specific practice.
Do I still need books if I use a platform like QuantVault?
Yes — they are complements. The books (the Green Book, Heard on the Street, Joshi) teach the canonical methods and reasoning patterns but are static: no grading, no spaced repetition, no firm-specific layer. A platform like QuantVault is the practice layer that turns reading into recall with a large graded bank, firm funnels, and a coding judge. Read for method, then drill for volume and speed. See our best quant interview books guide for which book fits which role.
How long does it take to prepare for quant interviews?
A focused candidate with reasonable math and coding fundamentals can get interview-ready in roughly six to eight weeks: foundations and daily speed drills first, then probability, combinatorics, and coding depth, then firm-specific funnels and OA tests, and a final sharpening week of timed mocks and review. Stretch the timeline if you are rebuilding fundamentals or balancing a full-time job; the structure matters more than the exact length — a daily speed habit, a structured bank for reps, firm funnels near the end, and a community for intel.
Practice the real thing
QuantVault has 2,800+ quant interview problems with full solutions, intuition, and hints, firm-by-firm interview funnels, and an auto-graded coding judge. Start free.