Does an ERC-20 approval make a token eligible as collateral?

An ERC-20 approval only authorizes a contract to transfer a stated token amount. Eligibility still comes from the lending market's reserve or market configuration, collateral flag, oracle, ratio, and caps. A separate approval can remain valid even when the later supply or borrow transaction fails. EIP-2612 permits and Permit2 signatures change the authorization path, but they do not change whether Aave, Compound III, or Morpho accepts the asset.

Are ERC-4626 vault shares eligible for DeFi borrowing?

ERC-4626 vault shares qualify only where the exact share token and a compatible valuation path are configured. The standard supplies share-to-asset conversion functions, but a lending market must still accept the contract and price the underlying claim. Morpho accepts ERC-4626 shares as collateral, while its market definition excludes ERC-4626 loan assets. Aave or Compound III support requires an explicit listing and the relevant collateral parameters.

Why does a Uniswap V3 liquidity position need separate collateral support?

A Uniswap V3 liquidity position needs separate support because it is an ERC-721 non-fungible token, while mainstream pooled lending reserves expect configured fungible token contracts. Its value also changes with the selected price range, pool prices, and accrued fees, so a simple ticker price is insufficient. Specialized lending designs value such positions separately; the position does not inherit eligibility merely because underlying tokens such as WETH or USDC are supported.

Are native ETH and WETH interchangeable for collateral checks?

Native ETH and WETH are distinct assets for contract configuration, even though WETH wraps ETH at a one-to-one unit relationship. ERC-20 lending reserves usually reference the WETH contract, while an interface may wrap or unwrap native ETH through a gateway during the transaction. The supported ticker does not erase that distinction. The wallet must use the network, token form, and contract path the selected market expects.

Does a large market capitalization justify a high collateral ratio?

A large market capitalization does not by itself justify a high LTV or liquidation threshold. Protocol configuration also weighs executable liquidity, price volatility, oracle coverage, token mechanics, concentration, and correlations with the borrowed asset. Governance or market creators translate those inputs into ratios, supply caps, or debt ceilings. Two tokens with similar capitalization therefore receive different borrowing power when their liquidation paths and pricing quality differ.

What happens to collateral when the borrow transaction reverts?

A reverted borrow transaction leaves the EVM state unchanged, so the protocol does not create the debt or complete any collateral movement bundled inside that call. An earlier approval submitted as a separate transaction remains recorded because it already settled independently. If collateral was supplied in a prior successful transaction, it stays supplied. Read the final transaction status before treating an interface quote as an opened position.

Can receipt tokens from one lending protocol become collateral in another?

Receipt tokens become collateral elsewhere only when the second protocol explicitly lists their exact contracts and maintains a valid valuation method. Aave aTokens, Compound v2 cTokens, and Morpho vault shares represent different claims and accounting systems; none receives automatic support from its origin protocol. The second market must account for exchange-rate changes, redemption conditions, and underlying asset risk before assigning any collateral ratio.

DeFi

DeFi eligibility is determined by collateral ratios and supported assets

DeFi eligibility is the set of asset-listing, collateral, and loan-to-value rules a lending market uses to calculate borrowing power. A token must exist in the selected market, be enabled as collateral, have a usable oracle price, and leave enough value below the borrowing limit. Account mode, caps, and accrued debt can narrow that capacity further.

This breakdown focuses on the point where a supported deposit becomes real borrowing power. It separates token support from collateral status, then traces how ratios, caps, precision, and protocol design change the answer.

Mistaking a supplied token for eligible collateral

A supplied token creates borrowing power only when the selected market accepts its exact contract as collateral and the account has enabled it. Supported assets and eligible collateral are separate protocol states. On Aave, a supplied reserve can earn interest while its collateral toggle is off; Compound III likewise applies a separate collateral factor to borrowing accounts.

Supply support

Supply support answers whether the contract will accept a deposit, not how much debt follows from it. Aave reserve configuration includes separate controls for supplying, borrowing, collateral use, freezing, and caps. Compound III assigns each collateral token a supply cap and supports no more than 15 collateral assets in one Comet deployment; that deployment still exposes one base asset for borrowing. Morpho takes the isolated-market route: every market pairs one collateral asset with one loan asset and fixes five market parameters at creation. Those structural limits decide eligibility before account arithmetic begins.

Collateral status

A 0% loan-to-value setting gives a deposited asset zero borrowing power. On Aave, an isolated asset must also remain the account's only enabled collateral.

Read the collateral-enabled flag, LTV, supply cap, and account mode together. A positive balance without all four conditions is a supply position, not usable borrowing capacity.

Interest and transaction costs consume borrowing headroom

Borrowing costs reduce eligibility whenever accrued interest raises debt faster than collateral value rises, even though the original asset listing remains unchanged. Aave recalculates health factor from the outstanding borrow balance, so interest steadily consumes the buffer. Compound III expresses rate accrual against a 31,536,000-second year and stores collateral factors at 10^18 scale. Network gas does not enter LTV, yet it determines the cost of supplying more collateral or repaying debt. The liquidation bonus applies after the threshold; it never adds borrowing power.

How much can an eligible asset support?

An eligible asset supports debt up to collateral value multiplied by its active loan-to-value ratio, subject to caps and available market liquidity. Borrowing capacity sits below the liquidation boundary when the protocol separates LTV from liquidation threshold. That gap forms the account's initial price buffer.

Borrowing limit

The formula uses oracle-valued collateral, not wallet balance or token count. Multiply each eligible collateral value by its active LTV, then add the adjusted values in a pooled protocol. Subtract outstanding debt to find unused capacity. A second collateral asset receives its own LTV before aggregation. Supply caps and debt ceilings apply outside this equation, so successful arithmetic never guarantees acceptance. Available liquidity also limits the loan asset the market can deliver.

Liquidation boundary

On Aave V3, health factor equals weighted collateral value at liquidation thresholds divided by total borrow value. A value below 1 makes the position eligible for liquidation. When health factor sits above 0.95 and both collateral and debt values reach at least $2,000, the protocol permits liquidation of up to 50% of total debt. At 0.95 or below, or when either side is under $2,000, the limit reaches 100%. A partial liquidation must leave at least $1,000 of both debt and collateral, otherwise the position clears in full.

The borrow limit admits a new loan, while the liquidation threshold governs an existing position under stress. Confusing the two removes the intended buffer.

A chain and contract address define the asset

Asset eligibility follows a specific chain-and-contract pair, so matching the ticker alone never proves the deposited token belongs to a lending market. An Ethereum Mainnet USDC contract and a Base USDC contract represent separate onchain assets, even though both use the USDC symbol.

Ethereum Mainnet uses chain ID 1, OP Mainnet uses 10, Polygon PoS uses 137, Arbitrum One uses 42161, and Base uses 8453. Each network maintains separate token contracts and reserve configurations. An Ethereum Virtual Machine (EVM) address stores 20 bytes and displays 40 hexadecimal characters after the 0x prefix. Copying an address from another chain changes the asset, even when the wallet renders the same ticker. Lending interfaces resolve eligibility from the selected market's configured contract address.

Unit precision matters after identity is settled. ERC-20 makes decimals optional; its specification uses 8 as an example, while native USDC uses 6 decimals and WETH uses 18. Compound III requires 8-decimal price feeds and caps base-token precision at 18 decimals. Those scales convert raw balances into collateral values; a mismatch makes an integration reject the asset or calculate unusable amounts.

When do caps and modes override the ratio?

Caps and account modes override a positive collateral ratio whenever the reserve, market, or selected borrowing mode imposes a narrower operational limit. Aave supply caps, isolation debt ceilings, and Efficiency Mode (E-mode) permissions operate alongside LTV. Compound III enforces a separate supply cap on every collateral asset (detailed in DeFi wallets rundown ).

An Aave supply cap blocks additional deposits once the reserve reaches its configured amount, even when an account's personal LTV has room. A nonzero isolation debt ceiling marks the asset as isolated; the account then uses one isolated collateral asset and borrows only assets approved for that mode. E-mode applies category-specific LTV, liquidation threshold, bonus, and borrowing permissions. Selecting a category can improve ratios for closely related assets, yet it also narrows the borrowable set. Compound III checks its market-wide supply cap before accepting collateral, then applies the asset's borrow collateral factor to account capacity.

A 0% LTV remains decisive: the token can still be supplied in a supporting market, but it contributes $0 to new borrowing power. The relevant limit is the smallest one reached first.

Protocol designs encode eligibility differently

Protocol design determines whether eligibility comes from a shared asset list, a single base-asset market, or an immutable collateral-and-loan pair. Aave V3, Compound III, and Morpho encode those choices in different places.

Aave V3 pooled reserves

Aave V3 combines multiple reserves in one account calculation. Each enabled collateral contributes oracle value weighted by LTV, while liquidation thresholds determine health factor. Isolation Mode and E-mode modify the permitted combinations. WETH, wstETH, USDC, and GHO remain subject to their specific Aave market configuration. A separate page looks at this in detail.

Compound III base-asset markets

A Compound III Comet market lends one base asset, such as USDC, against configured collateral assets. Borrow collateral factors admit new debt, while higher liquidation collateral factors test existing positions. The contract supports at most 15 collateral assets, uses 8-decimal price feeds, and scales factors by 10^18.

Morpho immutable pairs

Every Morpho market fixes five parameters: loan token, collateral token, oracle, interest-rate model, and liquidation loan-to-value ratio, or LLTV. It holds one loan token and one collateral token rather than pooling a list. Morpho scales LLTV by 10^18 and its oracle price by 10^36. The approved LLTV set contains nine values: 0%, 38.5%, 62.5%, 77%, 86%, 91.5%, 94.5%, 96.5%, and 98%. Once a market is created, its five parameters remain immutable. A wstETH/WETH market therefore stays distinct from another pair using the same tokens but a different oracle or LLTV.

Use this five-point decision checklist before calculating a borrow:

Confirm the chain ID and collateral contract match the chosen market.
Check collateral use is enabled and the active LTV exceeds 0%.
Compare intended debt with LTV capacity, caps, and available liquidity.
Record the liquidation threshold or LLTV and all accrued debt.
Check the supply cap or isolation debt ceiling has remaining room.

The protocol design tells you whether to inspect a reserve, a Comet market, or one immutable Morpho market ID.

What changes eligibility after the deposit?

Eligibility changes after deposit when prices, accrued debt, governance parameters, collateral flags, or account modes alter the position's usable borrowing capacity. The supported asset itself can remain listed while the account becomes unable to borrow more.

Oracle prices change collateral value, while interest enlarges debt. Aave Governance can revise reserve LTV, liquidation thresholds, caps, borrowing permissions, and E-mode categories. Compound Governance can update borrow and liquidation collateral factors or a supply cap for a Comet market. Morpho differs because its five market parameters never change after creation, although oracle output and debt balance still move. A paused or frozen action also blocks the relevant transaction without rewriting the token's ERC-20 balance. These paths separate asset listing from transaction eligibility.

Recalculate after every borrow, repayment, collateral withdrawal, or mode switch. DeFi eligibility is an account-and-market state, not a permanent property of a ticker. Track remaining capacity before the borrowing or liquidation boundary.

DeFi eligibility questions worth asking

Does an ERC-20 approval make a token eligible as collateral?: An ERC-20 approval only authorizes a contract to transfer a stated token amount. Eligibility still comes from the lending market's reserve or market configuration, collateral flag, oracle, ratio, and caps. A separate approval can remain valid even when the later supply or borrow transaction fails. EIP-2612 permits and Permit2 signatures change the authorization path, but they do not change whether Aave, Compound III, or Morpho accepts the asset.
Are ERC-4626 vault shares eligible for DeFi borrowing?: ERC-4626 vault shares qualify only where the exact share token and a compatible valuation path are configured. The standard supplies share-to-asset conversion functions, but a lending market must still accept the contract and price the underlying claim. Morpho accepts ERC-4626 shares as collateral, while its market definition excludes ERC-4626 loan assets. Aave or Compound III support requires an explicit listing and the relevant collateral parameters.
Why does a Uniswap V3 liquidity position need separate collateral support?: A Uniswap V3 liquidity position needs separate support because it is an ERC-721 non-fungible token, while mainstream pooled lending reserves expect configured fungible token contracts. Its value also changes with the selected price range, pool prices, and accrued fees, so a simple ticker price is insufficient. Specialized lending designs value such positions separately; the position does not inherit eligibility merely because underlying tokens such as WETH or USDC are supported.
Are native ETH and WETH interchangeable for collateral checks?: Native ETH and WETH are distinct assets for contract configuration, even though WETH wraps ETH at a one-to-one unit relationship. ERC-20 lending reserves usually reference the WETH contract, while an interface may wrap or unwrap native ETH through a gateway during the transaction. The supported ticker does not erase that distinction. The wallet must use the network, token form, and contract path the selected market expects.
Does a large market capitalization justify a high collateral ratio?: A large market capitalization does not by itself justify a high LTV or liquidation threshold. Protocol configuration also weighs executable liquidity, price volatility, oracle coverage, token mechanics, concentration, and correlations with the borrowed asset. Governance or market creators translate those inputs into ratios, supply caps, or debt ceilings. Two tokens with similar capitalization therefore receive different borrowing power when their liquidation paths and pricing quality differ.
What happens to collateral when the borrow transaction reverts?: A reverted borrow transaction leaves the EVM state unchanged, so the protocol does not create the debt or complete any collateral movement bundled inside that call. An earlier approval submitted as a separate transaction remains recorded because it already settled independently. If collateral was supplied in a prior successful transaction, it stays supplied. Read the final transaction status before treating an interface quote as an opened position.
Can receipt tokens from one lending protocol become collateral in another?: Receipt tokens become collateral elsewhere only when the second protocol explicitly lists their exact contracts and maintains a valid valuation method. Aave aTokens, Compound v2 cTokens, and Morpho vault shares represent different claims and accounting systems; none receives automatic support from its origin protocol. The second market must account for exchange-rate changes, redemption conditions, and underlying asset risk before assigning any collateral ratio.