KETJU Research

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Dollar lending

MortgageFi

Not approved Too small to exit at size
Issued
2026-08-16
Last confirmed
2026-08-16
Next check due
2026-11-15
Chains
Ethereum · No freeze key, Base · Mixed control, Arbitrum One · Mixed control

MortgageFi’s live Pool model lets lenders deposit stablecoins into separate vaults that fund long-dated BTC or ETH purchases. Borrowers avoid price-based liquidation, but a missed-payment timer can place the position in default. That is not a risk-free exit promise. The 2026-08-16 DefiLlama adapter still measured about $0.80M in two Base contracts and one residual Arbitrum contract. The current application labels Ethereum and Base markets live and the old Base and Arbitrum vaults deprecated. A lending book this small cannot take advised client money. One practice advising 100 households moves $1M to $8M into a venue on the same research, and below the size floor that book could overwhelm exits. We do not open an individual review until it clears the floor. The mismatch between the adapter and live-market lifecycle, and lender redemption liquidity, remain separate blockers.

The research file

Mechanism applicability

The live Pool model is peer-to-pool lending. Stablecoin lenders deposit into a separate shared vault, and borrowers combine a down payment with pool capital to buy supported BTC or ETH exposure held by the mortgage contract. Lenders earn interest and fees. The protocol says it has no price-based liquidations, but missed scheduled payments cause default and the borrower loses the position. The term can run for up to 30 years.

Current observation and lifecycle perimeter

The DefiLlama API read on 2026-08-16 reported approximately $0.76M on Base and $0.05M on Arbitrum. Its adapter still counts two Base pool contracts and one Arbitrum pool contract. By contrast, the current MortgageFi market application identifies USDC-cbBTC on Base and USDC-WETH on Ethereum as live. It labels the old Base WETH and Arbitrum WBTC vaults deprecated and closed to deposits. We therefore record Ethereum, Base, and residual Arbitrum, but must match every counted balance to its current status before use.

Control, loss and exit applicability

MortgageFi publishes deployed pool contracts and audit reports for the Pool model. Lenders still bear duration, utilization, smart-contract, default-resolution, and stablecoin risks. Its Redeemer and secondary-market documents describe ways to convert an Earn position. But neither a UI route nor LP-token trading proves immediate liquidity at net asset value when a pool is highly utilized or deprecated. The announced peer-to-peer Matching Engine is targeted for Q3 2026 and is not treated as live.

Why the class rule decides

At approximately $0.80M measured by DefiLlama, a $1M advised sleeve would exceed the entire tracked pool system. Aave or Compound suppliers take open-ended overcollateralized exposure tied to use of the pool. MortgageFi lenders instead fund undercollateralized positions with set payment dates that may run for decades, so the liquidity and default paths differ. The shared version-1 size rule decides now. Reopen only after TVL stays above the size floor for 30 days, all live and deprecated balances are reconciled, and evidence supports proposed-size lender redemption and default resolution.

Research status

This is a capacity-unproven record for MortgageFi, not a quality rejection or approval. Reported TVL says how big the venue is, not what the client owns, who can change the rules, or how a position exits at a proposed size. The individual review opens when the protocol clears the size floor.

Sources

The claims above trace to these. Where a number could not be independently verified, the thesis says so.

Inherited controls

The research above describes the protocol layer. Every position also inherits the asset it holds and the chain it settles on. The layer with the most administrative power sets the position’s effective control; that describes control, not quality or suitability.

ChainVerdictControlControl constraint
EthereumApproved No freeze key No sequencer, no upgrade key, no operator who can be compelled. Rule changes require social consensus.
BaseApproved with limits Mixed control Coinbase, one regulated US company, operates the only sequencer, and admin keys can upgrade bridge contracts within ~7 days.
Arbitrum OneApproved with limits Mixed control a single sequencer orders >99% of transactions and admin keys can upgrade bridge contracts on a ~7-day timelock.
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