Fixed economics
Return schedule
Fuel Earn uses 10% simple annualized yield prorated by the exact term:
| Term | Term days | Fixed return on opening value |
|---|---|---|
| 6 months | 180 | 4.9315% (displayed as 5%) |
| 9 months | 270 | 7.3973% (displayed as 7.5%) |
| 12 months | 365 | 10% |
The Sway contract uses integer arithmetic and floors at each division. UI confirmation receipts reproduce the same raw-unit order.
Immutable fields
After opening, nobody can edit the collateral asset, collateral amount, signed opening price, promised USDC, term, maturity, opening time, or initial penalty. NFT transfers change ownership only.
Early exit
The initial 2,500 bp penalty declines linearly to 1,000 bp, remains at that level for the final day, and becomes zero at maturity. Penalties round up so the Vault never under-collects. All USDC return is forfeited on early exit.
Market fee
BondMarket charges 10 bp rounded up. It is deducted from seller proceeds; buyer payment equals the asking price.