Try today's question

A game pays +12 points with probability 0.4 and −3 points otherwise. What is its expected net payoff?

Decimals or fractions like 9/13 both work. You don't need an account.

QuantGauntlet is practice for quant trading, research and dev interviews. Every problem has a follow-up, because that's usually where interviews get hard.

Interviews don't stop at your first answer

You get the EV right, then they add a fee, pull a card from the deck, or ask what happens if the dice are loaded. Every problem here has a follow-up like that, so you get reps on the part that trips people up.

Opening

A game pays +12 with probability 0.4 and −3 otherwise. What is the expected payoff?

3 points

Follow-up

The game now charges a 1.2-point entry fee regardless of the outcome. What is the expected net payoff?

1.8 points

A look inside

A practice problem after a wrong first answer: the feedback says one more try, with confidence buttons, a hint and the option to see the solution.
You get a second try. Miss once and you can try again or take a hint before the full solution shows up. A clock runs at interview pace, and trader problems hide the calculator.
The trading pit: your private card, hidden cards, a live order book with bids and offers, an order ticket and the trade tape.
A card game with a real order book. Each player gets one card and the contract settles at the sum of all of them. Play friends or bots for three minutes and see who made money.
The options lab: a butterfly's payoff today and at expiry with sliders for stock, volatility, days and rate, and the position's Greeks.
An options sandbox. Set up a butterfly or a straddle, then drag spot, vol and time around and watch the P&L and Greeks move.

What's in it

Three tracks (trader, researcher and developer) with eight topics each.

1,260 problems, all written from scratch
Probability, EV, options, microstructure, stats, stochastic calc, take-home data cases, ML, C++, concurrency, SQL and order books. Each one has a full worked solution.
It tells you what went wrong
If your answer matches a common mistake, like forgetting a fee or counting a case twice, you'll see which one.
A market-making sim
You quote two-sided markets while some customers know the true value and some don't. Your score is the edge you actually captured, so a lucky settlement can't cover for bad quotes.
New numbers on repeats
When a question comes back, the numbers and code are different, so remembering the answer won't help. Anything you miss comes back after 1, 3, 7 and 21 days.

Pricing

The free plan covers a lot. Pro is for when you're deep in recruiting.

FeatureFreePro
Price$0$19 a month
Or $129 a year, or $49 for three months with no renewal. Students pay $15 a month. Monthly and yearly plans start with a 7-day free trial.
Questions168, across every topicAll 1,260
Timed mocks1 a monthUnlimited
Case studies–Included
Market-making and arithmetic drillsIncludedIncluded
Progress, review queue and notesIncludedIncluded
Start freeTry Pro free for 7 days

Questions

Are these real interview questions?

They're original. Every problem was written around the topics firms list in their public interview guides. Nothing is copied from a firm's question bank or from prep books.

Which roles is it for?

Quant traders, researchers and developers. You can switch tracks whenever you want, and each track keeps its own progress.

Can I cancel?

Yes, from your account page, whenever you want. You keep Pro until the end of what you paid for. The season pass just ends and never renews.

Do you offer group access for clubs?

Yes. If you run a quant club or a program, email us from the club address and we'll set up codes for your members.