Predictarium Start learning

Learn

We're writing the nine modules one at a time and putting each one up as soon as we're happy with it, so the first is open now and the rest will follow over the coming weeks. Every module finishes with a few exercises you can check against the practice markets, and they're all free while we're writing them.

MODULE 1

Prices are probabilities

We'd start here. When a contract trades at 63¢ the market is telling you it thinks 63%, and once that clicks you'll see why the Yes and No prices nearly always add up to a little more than 100.

Open now, 15 minutes
MODULE 2

Fees, spreads and your real break-even

The number on the screen isn't quite the number you pay, and we'll show you how to work out the probability you really need once the fee and the spread come off (it's where we see most beginners lose money without ever noticing).

Next to go up
MODULE 3

Expected value and your own forecast

You need your own number before a price means anything to you. This is how we turn a view into that number and then decide whether a small edge is worth the bother.

Being written
MODULE 4

How much to put on

We'll derive the Kelly criterion with you and then explain why we, like most traders, only ever bet a fraction of it. Being right doesn't help much if a bad week wipes you out first.

Being written
MODULE 5

Arbitrage and where it breaks

Two venues pricing the same event differently looks like free money. Usually it isn't, since the settlement wording or the timing is slightly different, and we'll show you how to check before you trust the gap.

Being written
MODULE 6

Making markets

Here you quote both sides and get paid the spread for holding risk you didn't choose. We'll cover how we'd manage the position that builds up while you're doing it.

Being written
MODULE 7

Esports markets

Best-of-three and best-of-five series have tidy maths behind them. Once you know it you can tell when a live price after the first map has moved too far or not far enough.

Being written
MODULE 8

Keeping score

Calibration and the Brier score are how you find out if your forecasts are any good. A month of honest scoring will teach you more than a lucky streak ever does.

Being written
MODULE 9

The simulation engine

This is a full season of simulated markets against the clock, fees included, so you can see what your process does over hundreds of trades before real money is involved.

Being built