How Reason works

The vault

Two vaults, one for USDT and one for USDC on BNB Chain. Each is an ERC-4626 vault: you deposit the stablecoin and get shares, and each share is worth more as interest builds up. Shares are a normal token you can hold or send.

The two markets

Each vault holds its whole balance in one of two lending markets, fixed when it was deployed: Aave v3 and the Venus core pool. Deposits go to the market the vault sits in. If that market refuses a deposit (a supply cap, a pause), the other one takes it.

Comparing rates

Aave gives a yearly supply rate. Venus gives a rate per block, so the vault turns it into a yearly rate with BNB Chain's block pace, which it measures itself: at most once a day it divides the blocks since its last check by the seconds since, so a block-time change on the chain is followed without anyone updating it. Only base rates count; Venus XVS rewards are left out.

Moves

rebalance() moves the whole vault to the other market. Anyone can call it, and a deposit calls it on its own, when both hold:

• the other market pays at least 0.20% a year more;
• at least 6 hours have passed since the last move.

The cooldown means a brief spike in one market's rate can't push the vault back and forth. A move only changes where the money earns; it can't send it anywhere else.

Withdrawals

withdraw or redeem at any time. The vault takes the money from its current market first, then from the other one. The limit is each market's free cash, the part not lent out: usually millions of dollars. maxWithdraw shows what you can take right now.

Fees

Protocol fees are used to buy back and burn the token. See the token page.

Safeguards and risks

• No owner, no upgrade, no pause. Nobody can change the markets, the fee or the rules, or move money out of the two markets.
• Market risk stays. Your dollars are lent out through Aave or Venus. If a market had bad debt or froze, the vault would carry it.
• Liquidity risk. If both markets are fully borrowed for a while, withdrawals wait until cash comes back.
• Tested on a fork of BNB Chain with the real markets: deposits, a month of interest, forced moves, the block-pace check, transfers. Not audited.

Contracts

BNB Chain, chain id 56.