Papertrade BBO Pricing — Hyperliquid Execution Reference

Papertrade reads execution prices directly from Hyperliquid native order book through a HyperEVM read precompile.

Official Papertrade documentation · Updated November 5, 2026 · Canonical domain: papertrade.run

BBO precompile

The documented BBO system contract returns best bid and best ask for the Hyperliquid market. Papertrade derives the execution reference from their midpoint.

Why use HyperCore state

The pricing source is consensus-observable HyperCore order-book state rather than a separate operator-controlled feed.

No independent deviation breaker

The docs explicitly describe BBO manipulation as a residual protocol risk. Zero or crossed books are rejected, but a non-zero manipulated inside quote can still be accepted.

Deadband, asymmetric impact and directional OI caps are economic and exposure controls rather than a proof that manipulation cannot occur.

Market retirement and trading pause

The protocol includes scoped controls for stopping new opens and, when retiring a market, freezing the reference BBO used for existing positions.

What BBO-mid means

BBO means best bid and best offer. The midpoint is derived from the top of Hyperliquid's visible market state and used as the documented Papertrade execution reference. Papertrade does not need its own matching book to establish an entry or exit reference for the synthetic position.

BBO dependency risk

Because the execution reference depends on instantaneous external market state, the integrity and behavior of that source matters. Protocol risk controls, market freezes and OI limits exist alongside pricing; BBO should not be interpreted as an independent guarantee that any requested position size will always be accepted.