How to Estimate Impermanent Loss Before a Deposit
Impermanent loss is the value gap between holding two tokens and keeping them in a pool as their prices change. To estimate it, start with the pool’s price ratio and model how far apart the token prices could move while you are deposited.
- A twofold price move in a basic 50/50 pool creates about 5.7% impermanent loss before fees.
- The loss compares your pool position with simply holding the same starting tokens.
- Fees may offset the gap, but they are not guaranteed to do so.
Start With the Pool’s Price Ratio
A liquidity pool holds tokens so traders can swap between them. A liquidity provider deposits tokens into the pool and earns a share of trading fees. For a simple 50/50 pool, the starting value of each token is equal. If you want to explore providing liquidity on BaseSwap, first identify the two tokens and the pool’s starting price ratio.
Impermanent loss measures how your pool position compares with keeping those same tokens in your wallet. It is not a loss against the amount you first deposited; it is a shortfall against the “hold” comparison. The Ethereum.org glossary describes it as a shortfall when the pooled assets’ prices diverge.
For the estimate, use the price of one token relative to the other. If one token rises from $2,000 to $4,000 while the other stays at $1, the relative price has doubled. That is a price factor of 2.
Calculate the Gap With a Worked Example
For a basic 50/50 pool, use this formula: impermanent loss = 2 × √r ÷ (1 + r) − 1. Here, r is the new relative price divided by the starting relative price. The result is a percentage against holding, before fees.
For example, imagine depositing 1 ETH and 2,000 USDC when ETH is worth $2,000. Your starting deposit is worth $4,000. If ETH doubles to $4,000 and USDC stays near $1, the factor is 2. The formula gives about −5.7%.
In a basic pool, traders buy the token that has become cheaper inside the pool and sell the one that has become dearer. This trading shifts the pool’s token amounts until its price tracks the outside market. After the twofold move, your pool share would hold roughly 0.707 ETH and 2,828 USDC, worth about $5,657. Holding the original tokens would be worth $6,000. The gap is about $343, or 5.7% of the hold value.
The Uniswap v2 whitepaper explains this constant-product pool mechanism. The calculation is an example for a simple pool, not a forecast for every pool design. BaseSwap pool types can differ, so check the pool’s mechanics before applying this estimate.
Decide Whether Fees Could Offset the Gap
Impermanent loss is only one side of the comparison. A pool may earn trading fees, which can reduce or outweigh the gap. But fees depend on trading activity, your share of the pool, and how long you stay in it. Treat future fees as uncertain rather than subtracting a promised amount from your estimate.
The key decision is whether likely price movement and fee income suit your plan. A pool with tokens that often move in different directions can have a larger gap. If their relative price returns to its starting level, the gap can shrink; withdrawing while prices remain apart makes the difference real for you.
Before depositing on BaseSwap, compare the two-token pool position with the tokens you would hold outside it. Check token names and addresses carefully, since tokens can share similar names. BaseScan, a public Base network explorer, can help you inspect token contract details.
Common Questions About Impermanent Loss
Does a 5.7% estimate mean I will lose 5.7% of my deposit?
No. In the example, 5.7% is the pool position’s shortfall against holding the same starting tokens, before fees. The pool position still rose in dollar value as ETH rose. The estimate does not include trading fees, token price changes beyond the example, or other costs.
Why is it called “impermanent” loss?
The gap can shrink if the tokens’ relative prices return to their starting ratio while your deposit remains in the pool. The name does not mean the gap must reverse. If you withdraw while prices remain changed, the difference against holding is realized in the tokens you receive.
Can fees make up for impermanent loss?
Yes, fees can offset the gap, but the amount varies with trading activity and your share of the pool. A quiet pool may earn little. Compare any fee estimate over your expected deposit period with the price movement you are willing to accept, and remember that neither is certain.
Does this formula work for every liquidity pool?
No. It is a useful estimate for a basic pool that keeps equal values of two tokens and follows the constant-product design. Other pool designs may use different rules, including price ranges. Check the specific pool’s mechanics before relying on the result, and treat this example as a starting point.