The reference

Where the HyperCore mid comes from, how the basis is measured, and what the keeper can get wrong.

The keeper today

A keeper reads HyperCore spot books @107 (HYPE/USDC) and @334 (KNTQ/USDC) and posts one transaction for every market: the mid as a sqrtPriceX96, the basis in ppm, the HyperCore timestamp in ms and a sequence number. It posts when any mid moves 0.10% since the last post, plus a 60-second heartbeat. HYPE/KNTQ uses @107 ÷ @334 as a one-minute median because the KNTQ book is thin.

An arbitrageur who sees the same move can land a swap ahead of the post by paying a higher priority fee, and that swap pays the old, smaller fee. Day one captures most arbs, not all.

The Elysium basis

The basis is the 15-minute median of Elysium price ÷ HyperCore mid, measured on the deepest Elysium pools of the pair that are not Liquidisium pools: HYPE/USDC 0.30%, 0.20% and 1%, and HYPE/KNTQ 0.30%. The feed clamps it to ±5% and lets it move at most 0.25% per 10 minutes.

What a wrong post can do

The reference never moves a pool's price and never touches funds. It only sets the fee, which stays between 0.05% and 3%. A wrong reference can make a real arb cheap (LPs are then where they would be in any pool) or make honest swaps in one direction pay more, never above the reference price. Older than 120 s or more than 10% away, it is ignored and the pool charges 0.30%.

After EL1Read

EL1Read lets a contract read the HyperCore book inside the call. The adapter's source changes through the timelock, the hook does not. The basis becomes an onchain EMA updated on every Liquidisium swap, and the keeper leaves the price path.