How are prediction markets on Hyperliquid different from Polymarket?
From the outside, a prediction market is the same thing everywhere. You pay something under a dollar for a claim on an outcome, and if the outcome happens you collect a dollar.
The mechanics underneath are not the same, and the differences are not cosmetic — they determine what you actually own, what it costs to get in and out, and which specific things can go wrong. BT365 runs both Polymarket and Hyperliquid's HIP-4 outcome markets, so this is a comparison from having implemented against each rather than from reading their docs.
What you hold
This is the difference everything else follows from.
On Polymarket, you hold a token. Each outcome is a conditional token on Polygon, and buying a position means acquiring those tokens through an order book. When the market resolves, the tokens become redeemable on-chain, and redemption is a transaction — one that you (or the platform acting for you) submit. The winning outcome's tokens are worth a dollar each; the others are worth nothing.
On Hyperliquid, you hold a position. HIP-4 lists each outcome as a market on the exchange's own order book. Buying does not mint anything on-chain; it opens a position in your exchange account, priced strictly between zero and one, which the venue settles to zero or one at resolution.
So the question "what happens at resolution?" has two different answers. On Polymarket, something has to be redeemed, by someone, on-chain. On Hyperliquid, the venue marks your position to its terminal value and the balance changes.
Which means the failure modes are different
Both are fine when everything works. They break differently.
Polymarket's failure mode is redemption. Redeeming is an on-chain transaction, and transactions need gas and can revert. A resolved position whose redemption fails is still yours and still worth a dollar a share — but the value has not been collected yet, and something has to retry until it is. Handling this properly means treating "resolved" and "collected" as separate states and never marking the second on the strength of the first.
Hyperliquid's failure mode is delisting. A market on an exchange can be removed. If it is removed after the outcome is known, settlement is unambiguous. If it is removed while the price is still mid-range — say it was trading at fourteen cents — then the position's terminal value is genuinely not determined by the last price it traded at, and something has to decide what the position was worth. That is a harder problem than it sounds, and guessing at it is how a platform silently pays the wrong amount.
This is not hypothetical. When Hyperliquid moved HIP-4 outcome markets from USDH to USDC as the quote asset, the USDH-quoted markets were settled and delisted as a batch. A venue-side change can end a market on its own schedule, which is a category of event on-chain conditional tokens do not have.
Price mechanics
Both venues price outcomes between zero and one, but the rules differ in ways that matter if you are placing orders programmatically.
HIP-4 enforces a strict range — a limit price must be greater than zero and less than one, never equal to either — with prices carried at six decimal places internally. Client orders are additionally held to at most five significant figures, matching Hyperliquid's general price rule, while fills and accounting snapshots may legitimately carry the sixth decimal. There is also a floor on order size: ten dollars of notional.
The five-significant-figure rule is the one that catches people. 0.38211 is acceptable; a price with more precision than that is rejected outright rather than rounded, so an order builder that computes a price by dividing has to quantise before submitting.
Where the odds do not add up
One thing both venues share, and it is worth saying because it is the most common misreading of a prediction market.
The price is not a probability. It is what the last trader was willing to pay. Across a set of mutually exclusive outcomes, the prices need not sum to one, because each outcome trades in its own book against its own buyers and sellers, and nothing mechanically forces the books to agree. Polymarket's grouping mechanism does enforce that exactly one outcome pays out — that is a settlement guarantee, not a pricing one.
When the prices do not sum to one, the gap is real and, in principle, collectable. In practice, closing it means trading every leg at the displayed price, which is where order book depth and fees eat most of what looked like free money. We wrote about why prediction market odds don't add up separately, and the arithmetic there applies to both venues.
Which one you actually want
There is no universal answer, but the trade-off is clean.
Polymarket has the deeper markets on political, cultural and event outcomes, and the largest set of them. If the question you want exposure to is a news event, that is usually where the liquidity is. You are also holding a real on-chain claim, which some people prefer on principle.
Hyperliquid puts the outcome next to everything else you trade. Because the position lives in an exchange account, it draws on the same collateral as your other positions there rather than sitting in a separate wallet on a separate chain, and getting in and out does not mean bridging. If you are already trading perps on Hyperliquid, an outcome position is a market away rather than a chain away.
The corollary is worth stating explicitly, because it is the part people miss: sharing an account means sharing collateral. An outcome position on an exchange account is not walled off from the rest of it. That is convenient and it is also exposure — the same trade-off that applies to any unified margin account.
Part of our guide to how prediction markets actually work.
BT365 runs prediction markets on both Polymarket and Hyperliquid, alongside perps and spot, from one self-custodial account. Explore the platform or read the documentation.