HIP-4 mechanics
Pricing, fees, settlement, and the minimum-order math you need to size positions correctly.
Pricing#
A HIP-4 contract is a binary claim that pays 1 USDC if the outcome resolves true and 0 otherwise. (Early testnet iterations settled in USDH; mainnet HIP-4 settles USDC — no USDH is involved anywhere.) The market quotes a price in the range (0, 1) representing the implied probability.
Each side of a binary market has its own asset id, derived from the outcome index:
asset_id = 100_000_000 + (10 × outcome_index + side)Where side is 0 for YES and 1 for NO. The L2 book is subscribed by coin form (#<encoding>) for outcomes, separate from the perp coin name.
Fees#
HIP-4 has an asymmetric fee schedule that's important to internalise:
| Action | Taker | Maker |
|---|---|---|
| Open | 0 | 0 |
| Close | charged | charged |
| Burn / settle | charged | charged |
- Opens are free on both sides. Makers do not receive rebates on opens.
- Builder-code revenue accrues only on close / burn / settle. This is the only place builder fees are charged.
- Fees are paid in the pair's
feeToken, not always USDC. For the BTC daily, the fee token is USDC.
If you pair an outcome leg with a perp (Protect or Pair intent in the workstation), the perp side carries HL's standard taker fee schedule — independent of the outcome's zero-fee open. The workstation classifies the perp's pair tier:
| Perp tier | Taker fee (entry tier) | Example |
|---|---|---|
| Standard | 4.5 bps | BTC, ETH, SOL — volatile underlying |
| Aligned | 3.6 bps (20% off) | underlying aligned with quote token |
| Stable | 0.9 bps (80% off) | underlying is itself a stablecoin |
The resolved tier appears inline in the "Fees + funding (est.)" tooltip, alongside the per-side dollar amounts and a funding estimate over the remaining settlement window.
Minimum order#
HIP-4 enforces a notional floor of 10 USDC per order — plain order notional:
size × price ≥ 10 USDCHedgepit's order pad computes this live as minSize = ⌈10 / price⌉ and gates submission. If you try to send a smaller order via the API directly, the L1 rejects it with "Order must have minimum value of 10 USDC".
A favorite trading at 0.95 therefore needs only 11 contracts ($10.45) — the floor scales down in contracts as the price rises. (An earlier reading of the rule as size × min(markPx, 1 − markPx) was wrong: live books rest small high-priced asks that formula would forbid.)
Settlement#
The validator set publishes the resolution at the settlement time (06:00 UTC for the BTC daily). Open positions are marked to 0 or 1 instantly; PnL accrues, the close-side fee is charged in the fee token, and the position closes.
There is no "claim winnings" step — settlement is automatic and atomic.