DeFi generates the most complicated tax positions in crypto, and the gap between what people do and what the rules imply is wider here than anywhere else.
Adding liquidity is already two disposals
Supplying ETH and USDC to a Uniswap-style pool feels like a deposit. From a tax perspective it is two disposals. You disposed of the ETH at its market value, and you disposed of the USDC at its market value. In exchange you received an LP token.
This has an immediate consequence: the entire value of your deposit is a taxable event at the moment you add liquidity, even though you have not taken any profit out of the protocol. You have realised gains on both legs and now hold an asset whose basis you need to establish.
What is that basis? For a constant-product pool, the LP token’s value at deposit equals what you put in, so the basis is straightforward. For rebalancing pools and concentrated liquidity positions, the accounting is harder because the pool’s composition shifts over time.
Removing liquidity
When you withdraw, you dispose of the LP token for whatever you receive. That is the second disposal. The gain is the value received minus your basis in the LP token.
The compounding problem is impermanent loss. If the pool’s underlying assets moved in your favour while you were in it, part of that gain shows up as impermanent loss, which reduces the total value relative to simply holding. If the pool is worth less at withdrawal than at deposit, that difference is your loss, offset against the disposal gain. In a stable pair the arithmetic is manageable. In a volatile pair it becomes genuinely difficult.
Yield farming
Staking an LP token for a reward token means receiving new tokens, which raises the income question again. Applying the staking logic: where you had a right to the reward before the transaction generating it, the reward is income at receipt; where you did not, it is not, and you simply gain a basis.
Compound rewards add another layer. Auto-compounding deposits part of each reward back into the pool, which is a further deposit and therefore a further pair of disposals. A year of auto-compounding can generate an enormous transaction count for what looks like a single investment decision, and the disposals are real even though nothing was withdrawn.
Lending
Supplying assets to a lending protocol is generally treated as a non-taxable deposit, because you retain a claim to the same asset and no disposal has occurred. Interest received is income at receipt, with basis set accordingly.
Borrowing is different. Taking a loan against collateral you already own is generally not a taxable event, but the collateral remains your property and any liquidation of it is. If a loan is liquidated, the loss on your collateral is generally not deductible in the US, because personal property losses are limited to casualty or theft.
Bridging
Moving tokens between chains via a bridge is the least settled area in all of DeFi taxation. Whether the bridge deposit is a disposal and the receipt on the destination chain is a new acquisition, or whether the whole process is treated as a non-taxable transfer of the same property, depends on whether the bridge actually takes custody. Canonical bridges that lock and mint generally argue for non-taxable treatment on the basis that you never disposed of anything. That argument is reasonable and untested.
Why software helps most here
Every other category on this site is arithmetic once you have the transactions. DeFi is a data problem first: a single liquidity pool interaction can produce a deposit disposal, an LP token receipt, a reward receipt, and a compounding re-deposit. Across a year of automated strategies that is thousands of events across a dozen protocols and five chains, each needing correct categorisation.
Tools that import on-chain history and apply DeFi-specific categorisation are doing genuine analytical work here, not just arithmetic. In our testing the difference between platforms was widest precisely on this category — some required manual overrides for every pool interaction, others handled them without intervention.
What still needs a professional
Three questions no tool answers: how a specific bridge should be treated, whether your particular strategy involves a right to rewards before generation, and how a slashing or liquidation loss is treated in your jurisdiction. These are legal judgments on facts a tool cannot see. Build the transaction history with software, then take the open questions to an accountant.
This is general information, not tax advice. DeFi treatment is unsettled and varies by jurisdiction — confirm your position with a qualified tax professional.