Better Coinbase Mortgage Risk: Your Bitcoin Becomes an IOU

In early September 2026, CoinDesk reported a detail about the Better and Coinbase crypto mortgage that rarely makes it into the marketing: the Bitcoin a borrower pledges to back the loan can be rehypothecated. In plain terms, the lender can lend your coins out to a third party while your mortgage runs.

For a product built on the promise that you keep your Bitcoin instead of selling it, that is a meaningful footnote. If your collateral can be reused, what you hold is no longer your specific coins. It is a claim, an IOU, that depends on a counterparty being able to give those coins back.

Anyone searching "better coinbase mortgage risk" right now deserves a plain explanation. Here is what rehypothecation means, why it changes the risk of a crypto-backed mortgage, and how Milo's custody model is built differently.

What rehypothecation actually means

Rehypothecation is when a lender takes collateral you posted and reuses it, usually by lending or pledging it to someone else to earn a return. It is a normal practice in parts of traditional finance, but it changes what you own.

When you pledge Bitcoin and it can be rehypothecated, your position quietly shifts from "I own Bitcoin that is held as collateral" to "I am owed Bitcoin by a company." Those two things look identical on a good day. They are not the same thing at all on a bad one.

Why an IOU carries more risk than the coins

The 2022 crypto lending failures made this concrete for a lot of people. When several centralized lenders collapsed, customers who believed they had simply deposited assets discovered they were unsecured creditors in a bankruptcy, waiting in line to recover cents on the dollar. The common thread was that their assets had been lent out and reused rather than held aside for them.

Rehypothecation reintroduces that exact exposure inside a mortgage. If the party your coins were lent to defaults, or the chain of claims breaks somewhere you cannot see, you may end up as a creditor rather than an owner. On top of that counterparty risk, pledged coins in this structure are effectively locked for the life of the mortgage, so you cannot move them to safety if you get uneasy.

What reporting says about the Better and Coinbase structure

According to CoinDesk's September 6 reporting, the Better and Coinbase conforming mortgage allows pledged Bitcoin to be rehypothecated. The product reached general availability with a pre-application pipeline reported to top $360 million, and it depends on the government-backed conforming system, which ties its terms to Fannie Mae policy.

That regulatory dependence is not hypothetical. In August 2026, seven U.S. senators wrote to the Federal Housing Finance Agency raising concerns about the product's cost and its use of a volatile asset as collateral. We covered that in detail in our breakdown of the Senate warning. Rehypothecation adds a second layer to the same question: not just what the loan costs, but who is allowed to touch your coins while it runs.

How Milo handles collateral differently

Milo has been lending against crypto since 2021, and it takes a different path to the same goal of buying a home without selling your stack. You can see how the crypto-backed mortgage works in full, but the custody point is the one that matters here.

Milo does not rehypothecate customer crypto. Pledged assets are held with a qualified, regulated custodian in a segregated account, which means your coins stay your coins for the life of the loan rather than being lent out to earn a spread for someone else. If you want to understand why the custodian arrangement matters, our piece on crypto custody and pledged collateral walks through it.

A few other things are worth being straight about. Posting crypto as collateral with Milo is an option, not a requirement for every borrower, and clients can qualify based on their crypto wealth rather than the usual stack of W-2s and tax returns. For clients who do pledge crypto, Milo can finance up to 100 percent of the purchase price, and because you are not selling, you do not trigger a capital gains tax event on the coins you keep.

It also pays to be clear-eyed about risk. Like any crypto-collateralized loan, Milo's product includes margin calls, and pledged crypto can be liquidated if its value falls below the required level. How much cushion you have depends on how much you post: the more collateral, the more room prices can move before a margin notice is triggered. Custody is a separate question from that. It is about who is allowed to use your coins while they sit as collateral, and the answer at Milo is no one.

Five questions to ask any crypto mortgage lender

Whichever lender you are weighing, these questions surface the custody and counterparty risk that the advertised rate never shows:

1. Can my pledged crypto be rehypothecated or lent to a third party at any point?
2. Who custodies my collateral, and is it held in a segregated account in my name?
3. If the lender or one of its counterparties fails, am I a secured owner or an unsecured creditor?
4. Can I see the custody terms in writing before I sign anything?
5. Are there margin calls, and how far can prices fall before one is triggered?

A lender that answers all five plainly is one worth taking seriously.

The bottom line

The appeal of a crypto mortgage is simple: keep your Bitcoin, buy the home. Rehypothecation quietly chips away at the first half of that promise, because coins that can be lent out are no longer fully yours. The distinction between owning your collateral and holding an IOU for it is easy to miss when a product is new and the marketing is polished, and it is exactly the kind of detail worth checking before you commit six figures of crypto.

If you want to see what buying a home with your crypto could look like without handing your coins to a rehypothecation chain, learn more at milo.io. For a side-by-side view of the market, see our full bitcoin-backed mortgage lender comparison.

Eligibility requirements apply and all loans are subject to approval. This article is for general information and is not financial advice.

The opinions expressed in the Blog are for general informational purposes only and are not intended to provide specific advice or recommendations for any individual or on any specific security or investment product.