Impermanent loss is the reduction in value a liquidity provider experiences compared to simply holding the same assets — it arises because automated market makers must rebalance your deposited tokens whenever prices shift. Understanding it is essential before you commit funds to any liquidity pool.
Why it happens
When you deposit into a liquidity pool on a decentralized exchange, you hand over two assets in a fixed ratio — typically 50/50 by value. The pool’s smart contract uses a mathematical formula (commonly x × y = k) to set prices and fill trades automatically. As outside market prices move, arbitrageurs step in to rebalance the pool, buying the cheaper asset and selling the more expensive one until the pool price matches the wider market again.
That rebalancing is the source of impermanent loss. The pool ends up holding more of whichever token fell in price and less of whichever token rose. When you withdraw, you get that rebalanced mix — not the original amounts you deposited. If you had simply kept the tokens in your own wallet, you would have benefited more from the winner’s price increase.
A concrete example
Imagine you deposit 1 ETH and 2,000 USDC into an ETH/USDC pool when ETH is worth 2,000 USDC. Your deposit is worth 4,000 USDC in total.
Now suppose ETH’s market price doubles to 4,000 USDC. Arbitrageurs buy ETH from the pool until its internal price catches up. When you withdraw, the constant-product formula means you now hold roughly 0.707 ETH and 2,828 USDC — worth about 5,656 USDC.
Had you simply held 1 ETH and 2,000 USDC, you would have 6,000 USDC. The difference — about 344 USDC — is the impermanent loss.
Insight: Impermanent loss is symmetric. It does not matter whether ETH doubled or halved; any divergence from the entry price ratio reduces your position relative to holding. A 2× price move in either direction creates roughly a 5.7% loss versus holding; a 5× move pushes that to about 25%.
How price divergence maps to loss
The table below shows approximate impermanent loss for a standard 50/50 pool at various price-change multiples (relative to entry):
| Price change (one asset) | Approximate IL vs. holding |
|---|---|
| 1.25× (up 25%) | ~0.6% |
| 1.5× (up 50%) | ~2.0% |
| 2× (doubled) | ~5.7% |
| 3× (tripled) | ~13.4% |
| 5× | ~25.5% |
| 0.5× (halved) | ~5.7% |
These figures assume no fees have been collected and no other variables apply. Real outcomes differ once you factor in the trading fees you earn.
Why “impermanent”?
The name reflects a key nuance: the loss only crystallises when you withdraw. If prices return to exactly the ratio at which you deposited, the divergence disappears entirely and you are left holding the same amounts you put in (plus any fees earned). Providers who deposited equal-value ETH and USDC and then watched ETH surge 3× would only lock in impermanent loss if they withdrew at that peak. If they waited for ETH to fall back to the original price, the loss would vanish.
In practice, prices rarely revert perfectly, which is why many experienced participants treat impermanent loss as a real, ongoing cost rather than a temporary accounting quirk.
Fees, rewards, and whether they compensate
Liquidity providers earn a share of every swap fee the pool collects — typically between 0.05% and 1% per trade, depending on the protocol and pool tier. High-volume pools can generate enough fee revenue to outweigh moderate impermanent loss. Protocols also often supplement fee income with governance token emissions (liquidity mining rewards).
The calculation you need to make is:
Net return = trading fees earned + token rewards – impermanent loss
If the pool sees heavy trading volume and the two assets move in a correlated way (e.g., two stablecoins), impermanent loss is minimal and fees likely win. If one asset is highly volatile and volume is low, impermanent loss can easily dominate. Always model the worst case before depositing.
Which pools are most and least exposed
High-risk pools
- Volatile / volatile pairs (e.g., ETH/ALT): Both assets can diverge sharply from their entry ratio.
- New or low-liquidity tokens: Price swings tend to be larger and harder to predict.
Lower-risk pools
- Stablecoin pairs (e.g., USDC/USDT): Both assets track one dollar, so divergence is tiny and impermanent loss is negligible. See stablecoins explained for more on how these work.
- Correlated asset pairs (e.g., ETH/stETH): Assets that move together in price keep the pool ratio relatively stable.
Some protocols have designed concentrated liquidity pools and other mechanisms to let providers choose tighter price ranges, which can boost fee earnings but also amplifies impermanent loss if price moves outside the range entirely.
Practical considerations before you provide liquidity
- Model your break-even. Estimate the annual fee income at realistic trading volumes and compare it to the impermanent loss at a plausible price range for both assets.
- Time horizon matters. Short-term deposits in volatile pools are especially vulnerable because fees have less time to accumulate.
- Token reward inflation. Liquidity mining rewards can look attractive but often come with vesting schedules and may lose value themselves.
- Gas costs. On networks where gas fees are significant, entering and exiting a pool adds a fixed cost that further raises your break-even bar.
- Smart contract risk. As with all DeFi activity, funds in a pool are subject to the risk that the protocol’s smart contract contains a vulnerability.
Key takeaways
- Impermanent loss occurs when the price ratio of your deposited tokens changes after deposit; the pool’s rebalancing mechanism means you hold less of the appreciating asset than you would have by simply holding.
- The loss is “impermanent” only in the sense that it disappears if prices return to the entry ratio; most providers should treat it as a probable cost.
- Larger price divergences produce larger impermanent losses — a 5× move in one asset can erase roughly a quarter of the value you would have gained by holding.
- Stablecoin and highly-correlated pairs suffer the least impermanent loss; volatile pairs suffer the most.
- Trading fees and liquidity mining rewards can offset impermanent loss, but this requires enough volume and the right conditions — it is never guaranteed.
- Always calculate the net return (fees minus impermanent loss) before committing capital, and account for smart contract risk as an additional, unquantifiable exposure.
Next up: Lending and Borrowing