Extended Perps

Rejected venues wait the longest for re-review; a rejection has to earn another look before the scheduled date.

REJECTED ON A CATEGORICAL US EXCLUSION, NOT ON A CLAIM THAT THE EXCHANGE IS CUSTODIAL. Extended’s Terms name X10 Ltd. and its affiliates and incorporate a restricted-country list that currently includes the United States; the legal page says no exceptions are made and expressly prohibits VPN circumvention. The Starknet product is technically stronger than many offshore perpetual venues: collateral remains in Starknet contracts, signatures are required for state-changing operations, and trading rules and settlements are checked on chain. But order matching, risk assessment, and transaction sequencing remain off chain, and EVM-wallet exits depend on Rhino.fi bridge liquidity. The published outage procedure also confirms that liquidations and conditional orders pause during downtime and resume after a 120-second post-only window. Those are underwritable operating facts, but none can overcome the product’s explicit ineligibility for the registry’s US-client population.

Kill criteria: the events that revoke this verdict
• Extended removes the United States from its Restricted Territories and publishes the registration or exemption permitting the product to serve this registry’s client base
• Off-chain order matching, risk assessment, or transaction sequencing causes an outage exceeding one hour or a documented client loss
• The insurance vault absorbs more than 5% of its capital in one day or its published 15% daily depletion constraint changes
• A proposed-size EVM withdrawal exceeds the documented six-hour upper window because Rhino.fi bridge liquidity is unavailable

The research file

Mechanism and architecture

Extended is a hybrid central limit order book for perpetuals. Order processing, matching, position-risk assessment, and transaction sequencing run off chain for speed; Starknet contracts validate trading logic and settle the resulting state transitions. The account’s private Stark key is required to create orders, transfer funds, or withdraw, while an API key alone is read-only. Assets remain in on-chain contracts, so X10 says it cannot custody or unilaterally transfer user funds. That sharply limits theft authority but does not eliminate liveness dependence on the matching engine, risk engine, sequencer, oracle inputs, API, or Starknet proving and settlement pipeline.

Legal entity and categorical eligibility bar

Extended’s Terms identify X10 Ltd. and affiliates as the service provider and state that Restricted Persons may not access the website, order book, matching engine, contracts, applications, or APIs. A separately maintained legal page currently lists the United States alongside the United Kingdom, Canada, China and sanctioned jurisdictions. It applies to residents, citizens, persons physically located there, and entities incorporated or registered there. The Terms emphasize that no exception is available and VPN circumvention is forbidden. That is more explicit disclosure than many protocols in the Phase 2 backlog provided, but for this mandate better disclosure makes the decision clearer: the product is not eligible for the intended client.

Control, liquidation, and loss allocation

On-chain validation prevents a matching engine from settling a transaction that violates the encoded trading rules, but X10 still controls the off-chain order and risk pipeline that determines whether a valid transaction is presented at all. When an account breaches maintenance margin, positions move through the documented liquidation logic. The Extended Vault acts as the insurance fund across pairs, subject to market-level limits and a global rule that the fund cannot be depleted by more than 15% in one day. Any residual insolvent loss therefore depends on fund size, market configuration, and the venue’s response after that daily bound, not merely on a user’s self-custodial signature. That tail allocation requires monitoring even in a bug-free contract.

Security and operating record

Extended publishes StarkEx and Starknet audit references and a live bounty offering up to $500,000 for a critical bug with unintended financial consequences, $50,000 for a high-severity liveness failure, and $5,000 for a medium API issue. No confirmed protocol-fund exploit was identified in the primary materials or DefiLlama record reviewed through this cutoff. The documentation does, however, treat outages as an expected operating state: during downtime conditional orders do not trigger and liquidations do not process; after restart, a 120-second post-only period permits cancellation and passive orders before normal matching and liquidations resume. A self-custodial venue can therefore still leave a client unable to manage risk in time.

Migration, exit, and comparison

Extended began migrating from StarkEx to Starknet in August 2025, ultimately force-closing remaining legacy positions at mark price and leaving a slow-withdrawal-only path for unmigrated funds. On the current system, Starknet-wallet users withdraw directly to Starknet. EVM-wallet users depend on Rhino.fi for Ethereum, Arbitrum, Base, BSC, Avalanche, or Polygon exits; documented large Ethereum withdrawals can take up to six hours and all timing varies with bridge liquidity. Compared with Derive, Extended uses Starknet validity proofs rather than an OP Stack application chain, but both retain centralized off-chain matching and both prohibit US users. Compared with no perpetual position, Extended adds leveraged-market, oracle, engine-liveness, liquidation-fund, and bridge-exit risks without an eligible client use case.

Sources

The claims above trace to these. Where a number could not be independently verified, the thesis says so.

• Extended documentation — Terms of Use · primary · accessed 2026-08-19
  Supports: X10 Ltd. legal entity, Restricted Person prohibition, VPN ban, service scope
• Extended documentation — restricted countries · primary · accessed 2026-08-19
  Supports: United States inclusion, residency, citizenship, location, and incorporation scope
• Extended documentation — technical architecture · primary · accessed 2026-08-19
  Supports: off-chain matching and risk assessment, on-chain Starknet validation and settlement, self-custody
• Extended documentation — platform outage procedure · primary · accessed 2026-08-19
  Supports: conditional-order and liquidation pause, 120-second post-only restart period
• Extended documentation — deposits and withdrawals · primary · accessed 2026-08-19
  Supports: Rhino.fi bridge dependency, EVM limits and processing times, Starknet direct withdrawal
• Extended documentation — liquidation logic · primary · accessed 2026-08-19
  Supports: insurance-vault role, market loss limits, 15% daily global depletion constraint
• Extended documentation — bounty program · primary · accessed 2026-08-19
  Supports: $500,000 critical bounty, liveness and API severity tiers
• DefiLlama — Extended Perps protocol data · secondary · accessed 2026-08-19
  Supports: Ethereum and Starknet perimeter, current TVL, derivatives classification

Inherited controls

The verdict above grades the protocol layer. Every position also inherits the asset it holds and the chain it settles on. The least safe layer sets the position’s grade, and the position table names which one that is.