Borrow against BTCB

Bitcoin collateral without leaving BNB Chain

Bridging bitcoin to Ethereum to borrow against it costs a bridge transaction and mainnet gas at both ends. If your bitcoin exposure already sits on BNB Chain as BTCB, none of that is necessary: Teller pools take it at 50% LTV and 15% APR, lending USDC there directly.

The token is at 0x7130d2a12b9bcbfae4f2634d864a1ee1ce3ead9c, and the ceiling is the highest BNB Chain offers, which is what you would expect for the asset operators grade most conservatively.

Three wrappers, three issuers

Teller accepts bitcoin through BTCB here, WBTC on Ethereum and cbBTC on Base. All three track the same asset and all three depend on a different party holding it: Binance for this one, BitGo for WBTC, Coinbase for cbBTC. Choosing between them is mostly choosing whose custody you accept and which chain you want the dollars on.

Rates differ more than the ceilings do. Check the row on cbBTC and WBTC before deciding, because the gap between them has been wide.

Sixty-five thousand bitcoin, on one contract

totalSupply on 0x7130d2a12b9bcbfae4f2634d864a1ee1ce3ead9c answers about 65,301 BTCB, and the contract names itself “BTCB Token”. Every one of those is a claim on a bitcoin Binance says it holds, so the supply figure and the reserve claim are the same number seen from two sides.

You can read the supply in one call. The reserve behind it is the issuer’s disclosure rather than something the chain proves, which is the distinction to hold on to with any custodial wrapper.

This contract has an owner, and that is the point

BEP-20 requires a token to expose getOwner(), which plain ERC-20 does not. BTCB answers it with 0xf68a4b64162906eff0ff6ae34e2bb1cd42fef62d, and owner() returns the same address. The role is live rather than renounced.

For a custodial wrapper that is the correct arrangement. New BTCB has to be issued when new bitcoin arrives in custody and retired when it leaves, so an address with the authority to do it is what makes the peg maintainable. It is the opposite of what you want from a fixed-supply token, where a live owner is a risk rather than a mechanism.

Eighteen decimals, where the other two use eight

This is the detail that catches people. WBTC and cbBTC both carry eight decimals, matching bitcoin’s own smallest unit. BTCB carries eighteen, the BEP-20 default. The balance means the same thing, but the raw integer behind it is ten orders of magnitude larger.

It matters wherever you type a number that is not a display amount: a manual approval, a script, a contract call built by hand. Read the decimals off the token rather than assuming bitcoin exposure implies eight of them, and let the interface size the approval whenever it can.

Gas that does not eat the loan

The approval and the borrow cost cents on BNB Chain. On a modest bitcoin-backed loan that is the difference between the cost of opening the position being a rounding error and being a real fraction of the interest.

The loan

Deposit BTCB, receive USDC, repay or roll on the due date. Every loan is fixed-term with no margin-call, so a price fall during the loan cannot liquidate your collateral. Rollovers run on BNB Chain, so the term can be extended at the rate on offer that day. Miss the due date and the collateral is forfeit.