Stake bfUSD

Overview

bfUSD is minted by depositing USDT or USDC into BitFi's stablecoin engine. USDT deposits are priced 1:1, while USDC deposits rely on Chainlink price feeds to keep the peg. After minting bfUSD, users can stake that collateral into the ERC-4626 compliant Horizon (hbfUSD) or Pulsar (pbfUSD) vaults to capture yield while keeping capital liquid.

Key Contracts

• BitFiStablecoin: ERC-20 representation of bfUSD with 6 decimals.

• BitFiStablecoinMinter (USDT / USDC): Two dedicated minters that accept the respective stablecoin and mint bfUSD; each minter enforces minimum deposit sizes and interacts with a shared price oracle when needed.

• StakedBitFiStablecoin (hbfUSD / pbfUSD): ERC-4626 vaults that issue yield-bearing shares (low-risk Horizon and high-risk Pulsar) based on a per-epoch ratio; each vault exposes offset controls such as settlementDelay, supplyCap, and currentRatio.

• BitFiStablecoinZap: Optional helper that deposits the underlying stablecoin directly into the selected vault, combining mint + stake in a single transaction.

ERC-4626 Deposit Helpers

• previewDeposit(uint256 assets) – returns share amount for the incoming bfUSD amount using the current epoch ratio (rounded down to avoid overminting).

• previewMint(uint256 shares) – returns the bfUSD required to mint the target number of shares (rounded up so the vault receives enough assets).

• deposit(uint256 assets, address receiver) – deposits bfUSD and mints shares to receiver; requires an allowance for the vault and checks the supplyCap.

• mint(uint256 shares, address receiver) – requests an exact share amount, automatically calculating the underlying bfUSD needed, then mints those shares once the vault receives payment.

• convertToShares / convertToAssets – expose the same ratio logic as previewDeposit / previewRedeem, useful for front-ends that show expected yields.

• maxDeposit, maxMint, maxWithdraw, maxRedeem – enforce per-epoch limits, including the vault's supply cap and available liquidity.

Deposit Workflow

1. Acquire USDT or USDC and approve the respective BitFiStablecoinMinter contract.

2. Mint bfUSD via the minter (mint or deposit style), mindful that USDT stays at 1:1 while USDC uses the Chainlink price feed for fair conversion.

3. Approve the desired StakedBitFiStablecoin vault (horizon or pulsar) to spend bfUSD.

4. Call deposit or mint on the vault directly, or use BitFiStablecoinZap to combine mint-and-stake in one transaction.

5. Use previewDeposit / previewMint to display expected share amounts and currentRatio / epochRatios to project future values.

Yield Notes

hbfUSD (Horizon) is capped at 100 million shares and targets ~15% APY with smooth, non-drawdown ratio growth. pbfUSD (Pulsar) is capped at 2 million shares and targets ~22% APY while the share price may fluctuate; a portion of Horizon's revenue plus an insurance buffer supplements Pulsar, and Pulsar's principal backstops Horizon if the low-risk pool experiences a drawdown.