Bitcoin loan LTV, liquidation and wallet control explained

An original BCS Journal guide.

Loan-to-value, or LTV, compares what you owe with the value of the collateral backing the loan. If the debt rises or the collateral falls in value, LTV increases. A position can become eligible for liquidation when it breaches the borrowing arrangement’s threshold.

Controlling the wallet connected to that position does not cancel those rules. This is the essential distinction when discussing self-custody and Bitcoin-backed borrowing: authority to manage a position is not an unrestricted right to move its collateral.

How do you calculate LTV?

LTV = outstanding debt ÷ collateral value × 100.

Use values in the same currency. The debt calculation should include whatever accrued interest and financed charges the arrangement counts. For an on-chain position, the relevant collateral price may come from its designated price feed rather than the exchange price you happen to be watching.

Technical documentation on on-chain liquidation describes debt-to-collateral valuation and protocol-defined liquidation eligibility. Implementations differ; a threshold from one market is not a rule for all Bitcoin loans.

A numerical example: 0.1 BTC and a $3,000 loan

Assume 0.1 BTC of collateral, $3,000 of outstanding debt and a hypothetical liquidation threshold of 60% LTV. For this example, reaching that threshold makes the position eligible for liquidation. Hold the debt and Bitcoin quantity constant and ignore interest and fees for the first calculation.

At the initial $100,000 price, LTV is 30%. The difference between 30% LTV and the 60% threshold is 30 percentage points. It does not mean a 30% Bitcoin price drop reaches the threshold. With debt fixed, a 50% fall to $50,000 does so in this example.

The threshold price can be calculated as $3,000 ÷ (0.1 BTC × 0.60) = $50,000 per BTC. If accrued interest instead takes the debt to $3,090, the threshold price becomes $51,500. A position can move closer to liquidation even without another purchase.

These are illustrations, not a current Bitcoin price, a BCS borrowing limit or a guaranteed execution price. Real thresholds, price feeds, rounding and liquidation conditions depend on the arrangement.

What happens during liquidation?

Liquidation uses collateral to repay debt under the applicable rules. In some on-chain designs, a third party repays part or all of the debt and receives collateral with an incentive. The borrower can lose more collateral value than the principal repaid. Partial versus full liquidation, incentives and timing are implementation-specific.

Do not assume there will be a phone call, a grace period or time to wait for a price recovery. A notification is not a guarantee that you can act before liquidation. Market movement and transaction delays can matter while you are trying to change the position.

What changes LTV before liquidation?

In the example’s $60,000 price scenario, collateral is worth $6,000 and LTV is 50%. If you repay $1,000 of principal, debt becomes $2,000 and LTV falls to about 33.3%, assuming unchanged prices and no other debt adjustments.

Adding collateral could also lower LTV, but it commits more assets without reducing debt. Withdrawing collateral or borrowing more raises LTV, all else equal. These are mechanical relationships, not a recommendation to add funds to a distressed position. The right response depends on the terms, available resources and risk you are prepared to accept.

What does self-custody mean when Bitcoin is collateral?

Outside a borrowing arrangement, self-custody generally means controlling the keys needed to authorize spending, rather than relying on a custodian to do it for you. A Bitcoin wallet manages signing credentials; it is not a box physically containing coins.

Once collateral is pledged, ask about three separate kinds of control:

• Wallet control: who holds the signing authority for your wallet, and what permissions have you granted?
• Position control: who can initiate borrowing, repayment or an allowed withdrawal?
• Collateral control: what mechanism holds or restricts the collateral, who can change that mechanism and when can it release or liquidate assets?

You can retain your wallet keys while the collateral sits outside an ordinary freely spendable wallet balance. A withdrawal can remain blocked until sufficient debt is repaid or collateral requirements are met. Calling a position “self-custodial” should explain those boundaries, not imply you can override them.

Is the collateral native Bitcoin or a representation of it?

That question matters. A system may work with Bitcoin transactions directly or with a token representing Bitcoin elsewhere. Those arrangements can have different custody, redemption, signing and network dependencies. For example, Bitcoin integration documentation describes canister-authorized Bitcoin transactions and a separate tokenized-Bitcoin architecture. The word “on-chain” alone does not distinguish them.

Before pledging assets, look for a clear explanation of what you deposit, where it goes, what your wallet controls and how you receive Bitcoin back. On-chain visibility can help you inspect a position; it does not prove the absence of software bugs, price-feed failures or access restrictions.

What BCS’s non-custodial design aims to do

BCS is being designed to connect a user’s wallet, borrowing position and card experience without taking custody of their Bitcoin or wallet keys. The precise collateral mechanism and withdrawal rules must still be understood before using any supported arrangement. BCS is in development, with access subject to future availability and provider terms.

For the payment side, read how Bitcoin-backed card spending works. For the debt side, see borrowing costs and repayment compared with selling.

Educational information, not financial, investment or legal advice. All figures and thresholds are hypothetical. Technology and liquidation risks apply. Technical sources illustrate possible mechanisms, not confirmed BCS integrations.