For users:
Cross margin has been enabled for HIP-3 DEXs on testnet. This is not enabled on mainnet yet, but is eligible for mainnet-level bug bounties as described here: https://hyperliquid.gitbook.io/hyperliquid-docs/bug-bounty-program. HIP-3 deployers must enable cross margin for a given asset before users can use cross margin to trade it.
With unified account, all cross margined perps with the same collateral asset share margin, even across multiple DEXs. However, the assets across different DEXs will be protected up to their maintenance margin to avoid ADLs caused by large price moves on other DEXs. This novel “protected cross margin” system protects system solvency without sacrificing user experience.
Cross margin is not intended for use with DEX abstraction, and interfaces should not allow these users to trade using cross margin. Users should use unified account or portfolio margin for the expected behavior of cross margin on HIP-3 assets.
For HIP-3 deployers:
Despite the system-level protection, users still take greater risk when using cross margin across DEXs with different deployers. To better protect users, mainnet validators will enforce that HIP-3 deployers only enable cross margin on assets that satisfy defined eligibility standards, including: sufficient observable liquidity, a reliable external oracle source, and resilience to price manipulation. In particular, each time the
externalPerpPx of an asset moves more than 50% relative to the start of day price, validators will conduct a review to determine whether the deployer should be slashed due to manipulation. Assets where 50% daily moves are expected more than once a month are ineligible for cross margin and are subject to deployer slashing.For reference, cross, isolated, and isolated-only are margin modes: https://hyperliquid.gitbook.io/hyperliquid-docs/trading/margining#margin-mode, whereas portfolio margin, unified account, standard, and DEX abstraction are account abstraction modes: https://hyperliquid.gitbook.io/hyperliquid-docs/trading/account-abstraction-modes