How prices move

Every price here is just a probability. A share trades between 1¢ and 99¢, and the price is the room’s estimate of the odds — 60¢ means “about 60% likely.” If the outcome happens, each share you hold earns you $1; if it doesn’t, it’s worth nothing.

The market maker behind every price

Behind every market is an automated market maker (an “AMM”) — a program that always stands ready to buy and sell every outcome. That’s why there’s always a price and you never wait for someone to take the other side, even on a brand-new market with nobody else in it yet.

It doesn’t guess the odds like a bookie — it prices off a fixed curve (the LMSR rule, common in prediction markets). Two things fall out of that math that you’ll feel while trading. First, the outcomes always add up to about 100%: buy one and its price rises while the others ease down to compensate, so the numbers stay a coherent set of probabilities. Second, how far a trade moves the price depends on the market’s depth — a deep, liquid market barely budges on a small trade, a thin one swings more, and a big order always moves it more than a small one.

It’s a true hybrid, not just the bot. The maker’s quotes sit on the same order book as everyone’s limit orders, and your trade simply takes whichever price is cheapest. You can be the market yourself: post a limit at your own price and it rests there for anyone — including the maker — to trade against.

And you can’t drain it. The most the maker can ever subsidize is capped, and prices stop at 1¢ and 99¢ — so no amount of trading breaks a market or pushes a price past those bounds. (Want the actual equations — the cost function, the softmax, the loss bound? They’re in the rules.)

Why a big order pays more

Because the price climbs as you buy, a large order doesn’t fill at a single price. You take the cheapest shares first, then pay a little more for each one further up the curve — so you end up with a blended price above where you started. (Traders call that gap “slippage.”) It’s also why the market is informative: your buying pushes the price toward what you believe, and the next person sees it.

Quick example. Say shares are offered at 40¢, then 42¢, then 45¢. Buying 100 doesn’t cost 100 × 40¢ — you sweep up the curve and pay a blended price a bit above 40¢. Want to go all-in? Tap Max on the trade ticket — it walks those offers for you and spends your cash without overshooting.

Two ways to trade

Market takes the best price available right now and fills instantly. Limit lets you name a price and wait — your offer rests on the book until someone meets it, and until then it’s liquidity everyone else can trade against.