TL;DR

Impermanent loss is the difference in value between holding tokens in a liquidity pool versus simply holding them in your wallet. When the price ratio between pooled tokens changes, the AMM automatically rebalances your position: you end up with more of the cheaper token and less of the expensive one. It’s called “impermanent” because the loss reverses if prices return to their original ratio, but becomes permanent once you withdraw.

How It Works

Imagine you put $500 worth of ETH and $500 worth of a new token into a pool ($1,000 total). A week later, the token’s price has tripled. You might expect your position to be worth more, and it is, but it’s worth less than if you had just kept those tokens in your wallet.

Here’s why: the AMM constantly rebalances your position as prices change. When the token price rises, traders buy the token from the pool (taking it out) and deposit ETH (putting it in). Your share of the pool gradually shifts: more ETH, fewer tokens. You end up selling the winner and accumulating the laggard, which is the opposite of what a holder experiences.

The math is straightforward. For a constant product AMM (x * y = k), if one token’s price doubles, your pool position is worth about 94.3% of what holding would be worth (a 5.7% impermanent loss). If the price goes 4x, the loss is about 20%. At 10x, it’s roughly 42%. Small price movements produce negligible IL, but the loss accelerates with larger divergence.

The “impermanent” part refers to the fact that if prices return to their starting ratio, the loss disappears entirely. But in practice, prices rarely return to exactly where they started, especially for newly launched tokens. Once you withdraw from the pool, whatever IL exists at that moment becomes a realized loss.

Trading fees can offset impermanent loss. A pool that processes high volume relative to its size generates significant fee income for LPs. The fundamental question is whether the accumulated fees exceed the impermanent loss over the holding period. For stable pairs with tight price ranges, fees almost always win. For volatile new tokens, the outcome is much less certain.

Try It Yourself

See how the founder buy changes pool composition: the Token Launch Simulator shows the price appreciation from the initial token purchase, which directly illustrates the rebalancing that causes impermanent loss for anyone who provided liquidity at the initial price. Try the Token Launch Simulator →

Related Concepts

• Liquidity Provider: The entity that deposits tokens into pools and bears impermanent loss risk
• Constant Product AMM: The formula that creates the rebalancing effect underlying impermanent loss
• Liquidity Pool: The smart contract where the LP position lives and rebalances
• Liquidity: Deeper pools don’t prevent IL, but they attract more volume which generates more fee income
• Spot Price: The current price ratio that determines the magnitude of impermanent loss

Frequently Asked Questions

What is impermanent loss in simple terms?

Impermanent loss is the cost of providing liquidity to an AMM pool compared to just holding the same tokens in your wallet. When the price of one token changes relative to the other, the pool automatically sells some of your appreciating token and buys more of the depreciating one. The resulting position is worth less than if you had done nothing.

How much impermanent loss occurs when price doubles?

If one token’s price doubles relative to the other, the impermanent loss is approximately 5.7% compared to holding. If the price goes to 4x, the loss is about 20%. If the price goes to 10x, the loss reaches about 42%. The relationship isn’t linear: small price changes produce very small losses, but large swings create significant divergence.

Can trading fees offset impermanent loss?

Yes, and that’s the core tradeoff of being a liquidity provider. High-volume pools generate more fee income, which can exceed impermanent loss and make the LP position profitable overall. Whether fees offset IL depends on trading volume, fee percentage, price volatility, and the time period. Volatile, low-volume pools are the most likely to produce net losses.

Why does impermanent loss matter for token launches?

During a token launch, the founder often acts as the initial liquidity provider. If the token price increases significantly after launch (which is usually the goal), the founder’s LP position experiences impermanent loss relative to holding the tokens. Understanding this helps founders plan their liquidity budget and set realistic expectations for their position value.

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