Perpetual Stable Swap
This conditional order type enables automatic rebalancing between two stablecoins by continuously trading whichever token you hold more of. The mechanism adds a configurable spread to generate profit from rebalancing activities.
Core Mechanism
The contract examines your holdings of both tokens and creates sell orders for whichever asset represents the larger balance. The trade targets balance equilibrium while applying a half-spread markup to the exchange rate.
Configuration Parameters
| Parameter | Description |
|---|
tokenA / tokenB | The two assets for swapping, typically stablecoins like USDC and DAI |
validityBucketSeconds | Controls order validity duration by bucketing time into fixed windows. Recommended: 604800 (one week) or 1209600 (two weeks) |
halfSpreadBps | Basis point markup above 1:1 parity. 10 = 0.1% markup, 100 = 1% markup |
appData | IPFS hash associated with the order |
Validity Bucket Calculation
validTo = ((currentTime / validityBucketSeconds) * validityBucketSeconds) + validityBucketSeconds
buyAmount = convertAmount(sellAmount) * (10000 + halfSpreadBps) / 10000
Operational Logic
Balance Assessment and Token Selection
The contract retrieves both token balances, normalizes them to a common decimal standard, then determines which token exceeds the other. The excess token becomes the sell asset.
Decimal Handling
Different token decimals receive automatic conversion. For example, converting 1000 USDC (6 decimals) to DAI (18 decimals):
1000 * 10^6 * 10^(18-6) = 1000 * 10^18
Key Order Characteristics
- Orders are always sell-type (
KIND_SELL)
- Partial fills are disabled
- No protocol fees apply
- Receiver defaults to
address(0), which routes tokens back to the owner
Validation
The system rejects orders where NOT_FUNDED occurs — meaning zero sell amount due to missing balance of the required token.
Practical Applications
Liquidity Provision
Maintain equal stablecoin amounts while automatically rebalancing as supplies deplete, earning spread on each trade.
Yield Capture
Exploit minor stablecoin peg deviations with modest spreads (0.1-0.5%) while maintaining original position exposure.
Portfolio Diversification
Distribute holdings across multiple stablecoins with automatic equilibration to mitigate single-asset depeg risk.
Implementation Note
The validity bucket system ensures identical orderUid values when queried within the same time window, preventing orderbook spam on CoW Protocol.Last modified on March 4, 2026
