Hyperliquid shipped HIP-4 in early May, opening up zero-fee prediction markets on its base layer. The upgrade lets users trade fully collateralized binary contracts — Yes/No wagers that settle at 1 or 0 — directly on HyperCore, the same on-chain CLOB that handles spot and perpetuals. It's a direct challenge to Polymarket's dominance, and it brings a new resolution model to the table.
How the markets work
HIP-4's outcome markets use a merged order book where buying Yes at price p is the same as selling No at 1-p. That's the same approach Polymarket uses, and it keeps liquidity concentrated on one side of the book. The contracts settle based on a `settleFraction`, with no fees on trades. Builders like Outcome and Stratium frontend launched daily Bitcoin price binaries on day one.
The integration isn't a side experiment. HIP-4 sits inside HyperCore, meaning prediction markets trade alongside spot and perps on the same matching engine. That's a structural difference from most prediction platforms, which operate off-chain order books with on-chain settlement.
Resolution model differs
Polymarket doesn't decide outcomes itself — it outsources resolution to decentralized oracles and other third parties. HIP-4, by contrast, uses a validator-based model where Hyperliquid's validators determine the settleFraction. That's a meaningful design choice, but it hasn't been stress-tested by a contested event yet. As of late May, no disputed market had put the mechanism under real pressure.
If a market is close or ambiguous, validators will have to make a call. Whether that process holds up under a genuinely controversial outcome is an open question.
Polymarket's run and Kalshi's surge
Polymarket remains the largest on-chain prediction market, and its numbers have been climbing fast. Monthly volume roughly sevenfold from late 2025 into 2026, peaking near $5 billion in March per DefiLlama — though Polymarket's own figures are about double that. The platform runs on Polygon, uses Gnosis Conditional Tokens, and settles in USDC.
But Polymarket isn't the only player. CFTC-regulated Kalshi has matched and recently outrun Polymarket in volume. So the competition is already fierce, and Hyperliquid is entering with a different technical stack and no fees.
Expansion to macro markets
In late May, Hyperliquid expanded HIP-4 beyond crypto binaries to macro events like US inflation prints and Federal Reserve decisions. That's a direct play for the same territory where Kalshi has built momentum. With zero fees and an on-chain CLOB, Hyperliquid is positioning itself as the venue for traders who want the speed of a central limit order book without leaving the chain.
The next test will be a high-stakes, contested market — the kind that forces the validator resolution model to make an unpopular call. That hasn't happened yet, but it's coming.
