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Everything quant, in one place.

A live market monitor, 1,903 interview questions with worked solutions, 22 hands-on tools, and a library that goes deep. All free, because none of it should sit behind a paywall.

Right now the market is stressedvol 14.6%High Beta leading +1.0%see the monitor →
1,903
practice questions
22
hands-on tools
127
core concepts
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Try it right now

No signup, nothing to install. Here are two of the site's tools, playable right on this page.

An interview questionflip to reveal
ProbabilityTap to reveal

A fair coin is flipped until the first heads. What is the expected number of flips?

Answer

2. It is geometric with p = 1/2, so the expected count is 1/p = 2.

The bell curve, livekeep clicking

Flip 10 coins, count the heads, repeat. Watch the normal curve show up on its own.

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Make a marketquote & trade

Quote a two-sided market on two dice, then trade. Can you stay in the black?

bid6@8ask

Fair value is 7 (the average sum of two dice). Capture the spread, but quote too wide and nobody trades.

P&L +0 over 0

What's inside

Six parts of the site, each built to do one thing. Start wherever you like.

Why this exists

Quant knowledge shouldn't hide behind a paywall.

Most of it is locked up in expensive courses, prestige programs, and PDFs passed around in private. That always felt backwards to us, so we put the whole kit, the monitor, the questions, the games, and the library, in one place and made it free. It stays free.

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