What Is Extended Exchange? The Starknet Perpetuals DEX Explained

The exchange first ran on Ethereum using StarkWare's StarkEx engine under the X10 name. On August 12, 2025, the Starknet version launched. The StarkEx version ran in parallel for two weeks, then switched to reduce-only mode, then shut down ¹⁰. At launch, Extended offered more than 50 markets. The docs now list 100+ ¹¹⁰. The team raised $6.5 million in 2024 from investors including Tioga Capital, StarkWare and Lido co-founder Konstantin Lomashuk ¹⁰.

Extended plans to move sequencing to its own app-chain, a validator network secured by Starknet. The docs present this as a roadmap item, with details to come ¹.

1. Fund the account. You deposit USDC, ETH, wBTC or USDT from Ethereum, Arbitrum, Base, Polygon, Avalanche, BNB Chain or Arc. Deposits go through the Rhino.fi bridge, and you can also deposit directly from Starknet. Most transfers take about 2 minutes. Large withdrawals can take up to 4 hours. Per-transaction caps are generally $10 million, or $1 million on some routes ⁵.
2. Trade. You place orders on an order book. The terms list the order book and matching engine as part of the interface. Trades settle peer-to-peer between user accounts through the protocol contracts ⁷.
3. Manage margin. Your equity is your USDC balance plus spot holdings plus unrealized profit and loss. Each position needs maintenance margin, which equals its size × mark price × the market's maintenance rate ⁴.
4. Withdraw back to a supported chain. How much you can withdraw depends on the margin your open positions require ⁵.

The terms say Extended never holds your private keys, and deposits into the protocol contracts do not transfer ownership to the company ⁷. The company can still restrict interface access for terms breaches or during network migrations ⁷.

Makers with at least 0.5% of 30-day maker volume earn rebates of 0.002% to 0.010%. Rebates are paid daily when they reach at least $10 ². Extended says it may change the schedule ². Bridge transfers can carry their own costs.

Funding is charged every hour. On crypto order-book markets, the rate is calculated over an 8-hour period and includes a 0.01% interest component. Each market group has an hourly cap, from 0.25% for the most liquid markets to 2% for the least liquid ³. Depending on which side of the market you are on, funding can either cost you or pay you.

• Extended sends margin calls when your margin ratio passes 66% and again at 80%. These are warnings only ⁴.
• When equity falls below maintenance margin (a ratio above 100%), the account is liquidated. If the liquidation closes at a better price than your bankruptcy price, a 1% fee goes to the Extended Vault ⁴.
• If a position cannot be closed within 5% of its bankruptcy price, or the vault's loss limits are reached, auto-deleveraging applies. Profitable, high-leverage traders on the other side have positions closed against the bankrupt one ⁴.

The vault's losses on liquidations are capped at 5% of its value per day, with smaller per-market and per-trade caps for less liquid markets ⁴.

When you deposit USDC into the Extended Vault, you receive XVS shares ¹⁸.

• What the vault does: it takes over liquidated positions (earning the 1% fee) and lends USDC in Extended's native money market. It no longer acts as a market maker ⁸.
• XVS as collateral: XVS counts at 90% of its value as trading collateral. XVS itself cannot currently be withdrawn from the exchange ⁸.
• Deposit rules: the minimum deposit is $5. Each deposit is locked for 24 hours. When you withdraw, the vault closes a pro-rata slice of its positions, and you bear the price impact ⁸.
• Risk: returns can be negative and you can lose all of your allocation. No insurance or guarantee covers the vault ⁸.

Extended's restricted list covers the United States, United Kingdom, Canada, Hong Kong, Russia, Iran, North Korea, Cuba, Syria, Iraq, Yemen, Afghanistan, Seychelles and the occupied regions of Ukraine. It also has a catch-all for anyone whose use would break applicable law ⁶. Using a VPN to get around these restrictions would violate the terms.

• Audits: ChainSecurity audited the Starknet perpetual contracts, and Code4rena ran a public competition in March 2025 ⁹. An audit lowers risk but does not guarantee safety.
• Leverage: at up to 100x, a small price move can wipe out your margin ¹⁴.
• Base-layer dependence: Extended relies on Starknet. Starknet halted block production for more than two hours on January 5, 2026. The report did not name Extended ¹¹.
• Bridge and oracle dependencies: transfers go through Rhino.fi ⁵, and liquidations depend on mark prices.
• Vault and ADL risk for XVS holders and profitable traders ⁴⁸.