Tools you can actually play with.

Quote a two-sided market, manage your inventory, and try to end in the black against a flow of noise and informed traders.

The trading-floor classic: answer as many arithmetic questions as you can before the clock runs out. Optiver-style 80-in-8.

Random questions from the 300-question bank, on a timer. Read, think, reveal, self-mark. Build a streak across probability, brainteasers and more.

A scatter plot flashes up, you guess its correlation. A fast, addictive way to train the single most useful stat instinct.

What number comes next? Spot the pattern before the timer runs out, a classic trading-interview warm-up.

Bet or fold? See a quick wager and decide if it's a good deal, on the clock. Trains the expected-value reflex traders live by.

Convert between decimal odds, fractional odds and probability at speed, the mental plumbing of every betting and options market.

How well do you know what you don't know? Rate your confidence on quant and markets facts, and get scored on how honest your probabilities are.

One chart is a real market; the other is pure randomness. Can you tell them apart? Most people can't, and that's the whole point.