Providing liquidity to a decentralised exchange sounds like easy money: deposit two tokens, earn trading fees, and withdraw whenever you want. But there is a hidden cost that catches most new LPs off guard. It is called impermanent loss, and understanding it is the single most important thing you can do before committing capital to any AMM pool.
How Automated Market Makers Work
Traditional exchanges use order books where buyers and sellers set their own prices. Automated market makers like Uniswap, SushiSwap, and PancakeSwap work differently. They use a mathematical formula to determine prices based on the ratio of tokens in a liquidity pool.
The most common formula is the constant product equation: x * y = k. Here, x and y are the quantities of each token in the pool, and k is a constant. When a trader buys token A from the pool, the amount of token A decreases and the amount of token B increases, which shifts the price. This is elegant and permissionless, but it creates a specific risk for anyone providing liquidity.
What Impermanent Loss Actually Is
Impermanent loss is the difference in value between holding your tokens in a liquidity pool and simply holding them in your wallet. It occurs whenever the price ratio of your deposited tokens changes from the ratio at the time you deposited them. The larger the price divergence, the greater the loss.
The word "impermanent" is important. If the token prices return to the exact ratio they were at when you deposited, the loss disappears entirely. You would have earned trading fees on top of your original position. But if you withdraw while the ratio is different, or if prices never return, then the loss becomes very permanent.
A Simple Numerical Example
Suppose you deposit $1,000 worth of ETH and $1,000 worth of USDC into a 50/50 pool. ETH is priced at $2,000, so you deposit 0.5 ETH and 1,000 USDC. The constant product k equals 0.5 * 1,000 = 500.
Now imagine ETH doubles to $4,000. Arbitrage traders rebalance the pool until the internal price matches the market. After rebalancing, the pool holds approximately 0.354 ETH and 1,414 USDC. Your share is worth about $2,828.
Had you simply held 0.5 ETH and 1,000 USDC in your wallet, they would be worth $3,000. The $172 difference is your impermanent loss, roughly 5.7% of what you would have had by just holding. At a 3x price change the loss grows to about 13.4%, and at a 5x change it reaches 25.5%.
Run your own impermanent loss scenarios with exact numbers using our IL Calculator.
When Does Impermanent Loss Become Permanent?
There are three scenarios where impermanent loss crystallises into a real, permanent loss:
- You withdraw at a different ratio. If you remove your liquidity while the price ratio differs from your entry ratio, the loss locks in. It does not matter whether prices moved up or down; any divergence creates IL.
- One token goes to zero. In the worst case, one token in your pair drops to near zero. The AMM rebalances by filling your position almost entirely with the failing token. You end up holding a pile of worthless tokens and almost none of the good one.
- You provide liquidity for a short period. Short time horizons give prices less opportunity to revert and give you less time to accumulate trading fees that offset the loss.
How to Reduce Impermanent Loss
You cannot eliminate impermanent loss from constant-product AMMs, but you can take steps to manage it:
- Choose stablecoin pairs. Pools like USDC/USDT or DAI/USDC have minimal price divergence between tokens, which means minimal IL. The trade-off is lower fee income because stable pairs generate less trading volume.
- Use concentrated liquidity carefully. Uniswap V3 lets you concentrate your capital in a specific price range. This earns higher fees per dollar deployed, but it amplifies impermanent loss if the price moves outside your range.
- Look for high-fee pools. A pool with a 1% fee tier accumulates fee income faster than a 0.05% pool. If the fees earned exceed the impermanent loss, you still come out ahead.
- Pair correlated assets. Tokens that tend to move together, like ETH and stETH, naturally maintain a tighter price ratio. Less divergence means less IL.
- Extend your time horizon. The longer you stay in a pool, the more fees you accumulate. Over months, fee income can substantially offset or even exceed the impermanent loss.
Should You Still Provide Liquidity?
Impermanent loss is not a reason to avoid liquidity provision entirely. It is a cost of doing business in DeFi, similar to how slippage is a cost of trading. The question is whether the trading fees and any additional incentives (liquidity mining rewards, governance tokens) are enough to compensate you for the risk.
Before depositing into any pool, calculate the break-even point. How much fee income does the pool need to generate to cover your worst-case IL scenario? If the pool consistently earns more than that, the opportunity is worth considering. If not, holding the tokens directly is the better strategy.
Every pool and every market condition is different. Run the numbers before you commit capital, and revisit them regularly as prices shift. The LPs who last in DeFi are the ones who treat impermanent loss as a quantifiable risk, not an afterthought.
Use our IL Calculator to model your exact impermanent loss before providing liquidity to any pool.