How Axis Works

Axis combines an offchain order and strategy system with onchain issuance and staking contracts. The end-to-end lifecycle below is how the V2 contracts are designed to behave once deployed.

1. Mint USDx

USDx, the Axis Dollar (Axis's synthetic dollar), is created through the USDx primary market (USDxMarket), a single contract that settles both sides of issuance as signed orders. An approved counterparty, a whitelisted, eligible participant, submits an order on the USDx market whose side is MINT and which specifies the collateral and USDx amounts. When the order is filled, USDx is minted at roughly 1:1 against the incoming collateral. An operator (holding MINT_OPERATOR_ROLE) submits the order onchain. The market validates the signature, expiry, nonce, supported collateral, custody route and channel, and current capacity before moving collateral to registered custody addresses and minting USDx. Interface, legal, and operational eligibility can impose additional conditions outside the contract.

Once collateral leaves the contract it is routed through the market's channels and lanes to a custodian account, and from there custody is transferred out to the exchanges and trading venues that hold the backing portfolio. By design, Axis takes no profit from minting or redeeming USDx, mint and redeem settle against the collateral in the order rather than at a margin for Axis. Where that collateral is custodied and how the backing is evidenced is covered separately in Backing, Custody & Transparency.

The amounts in the signed order define the transaction. The market does not use an external price oracle to calculate the mint quote.

2. Use or hold USDx

USDx is transferable as an ERC-20 token. Secondary-market price depends on market supply, demand, liquidity, and confidence in the mint-and-redeem pathway. Read How USDx Targets $1.

3. Stake USDx for sUSDx

Users can deposit USDx into the ERC-4626 rewards vault (StakedUSDx) and receive sUSDx. An sUSDx position is designed to represent a proportional claim on the vault's accounted assets.

$$\text{sUSDx value in USDx} = \frac{\text{vault total assets}}{\text{sUSDx total supply}}$$

4. Generate and distribute rewards

Axis's market-neutral trading engine covers cross-venue arbitrage, cross-currency arbitrage, funding rate arbitrage, and OTC/RFQ. The engine evaluates opportunities across these categories and allocates within its risk limits as market conditions change. Axis's structural edge is cross-venue and cross-asset fragmentation, a durable, market-neutral yield source that does not rely on any single mechanism. Funding is one component (and can be the larger share in a given period); see the Transparency Dashboard for current attribution.

When realized trading results are delivered to the vault as rewards, a reward manager (holding REWARD_MANAGER_ROLE) calls fundRewards to add them to the vault's linear vesting schedule. Vested rewards increase the vault assets represented by each sUSDx position.

Yield is therefore neither created by the token contract nor guaranteed by staking. The vault can only distribute rewards it actually receives, and only as they vest.

5. Unstake or redeem

Exiting sUSDx is an ERC-7540 asynchronous redemption, a request/claim lifecycle rather than an instant swap:

1. Request. The controller calls requestRedeem, which burns the owner's shares and moves the corresponding assets out of the vault's accounted assets into pendingRedeemAssets. The request snapshots its own terms, including an eligibleAt time derived from the cooldown parameter in force at request time. Cooldown is a property of the async request, not an optional add-on.

2. Service. A redemption servicer (holding REDEMPTION_SERVICER_ROLE) calls serviceRedemptions, which moves eligible pending requests to claimable, shifting their reserved assets from pendingRedeemAssets to claimableRedeemAssets.

3. Claim. Once claimable, the controller withdraws/claims the reserved USDx.

Redeeming the underlying USDx is the redeem side of the same primary market: a holder signs an order whose side is REDEEM, and an operator (holding REDEEM_OPERATOR_ROLE) settles it, burning USDx and returning the collateral specified in the order. Mint and redeem are two sides (OrderSide) of one market, not separate contracts.

Onchain and offchain responsibilities

Onchain contracts enforce	Offchain systems are needed for
Signature, nonce, expiry, and role checks	Constructing and submitting mint/redeem orders
Supported-asset and registered-custodian checks	Custody operations
Route, channel, and capacity limits	Strategy execution and venue access
USDx minting and burning	Determining order terms
sUSDx accounting, reward vesting, and the async redemption queue	Delivering realized rewards to the vault

This boundary matters for risk analysis. Contract safeguards can constrain onchain actions, but they cannot remove custody, venue, execution, or operator risk.