Why Is Impermanent Loss Called Impermanent If It Can Be Permanent?
The term “impermanent loss” trips people up because the loss it describes can, in practice, end up being entirely permanent. The name refers to a specific condition, not a guarantee about how things turn out.
The short answer
Impermanent loss is the gap between what a liquidity pool position is worth compared with simply holding the same assets outside the pool. It’s called “impermanent” because that gap exists only on paper while the assets remain in the pool — if relative prices return to where they were when the funds were deposited, the gap shrinks back toward zero. It becomes a real, locked-in loss only at the moment the funds are withdrawn while prices remain different from the starting point.
How the mechanics create this gap
Liquidity pools work by holding a pair of assets and automatically rebalancing their ratio as trades happen, so that the pool always offers both assets for exchange — one of several mechanics that make leverage in DeFi trading and automated market-making possible in the first place. When the price of one asset moves relative to the other, the pool’s automated rebalancing shifts its holdings toward more of the asset that fell in relative value and less of the one that rose. That means a liquidity provider ends up holding a different mix of assets than they deposited — typically more of the underperformer and less of the outperformer compared with just holding both directly. The difference in value between those two outcomes is the impermanent loss.
Why “impermanent” is the accurate word — sometimes
- While funds stay in the pool, the loss is unrealized. It reflects a comparison against an alternative strategy, not an actual reduction in the number of tokens held or their combined dollar value at that instant.
- If prices converge back to the original ratio, the gap closes. Because the pool’s rebalancing works in both directions, a full return to the starting price ratio brings the position back in line with what simply holding the assets would have produced.
- The name doesn’t promise reversal will happen. Prices might never return to their starting ratio, in which case the loss that was technically “impermanent” the whole time never actually reverses.
When it turns permanent
The loss locks in the moment liquidity is withdrawn from the pool while asset prices remain different from their ratio at deposit. At that point, the comparison against simply holding the assets becomes a completed fact rather than a hypothetical one — there’s no longer a pool position that could benefit from prices moving back. This is one reason real yield is often discussed separately from inflationary yield in liquidity provision: returns earned from trading fees need to outweigh this locked-in loss, not just the paper version of it, for the position to have been worthwhile overall.
What to weigh before evaluating a pool position
Impermanent loss is a structural feature of how automated liquidity pools work, not a sign of something going wrong. It grows larger the more the two pooled assets diverge in price from each other, and it’s smallest when both assets move together. Fees earned from the pool can offset some or all of it, but there’s no guarantee those fees will be enough, and the underlying assets remain subject to the same volatility, irreversibility of on-chain transactions, and lack of FDIC or SIPC coverage as any other crypto holding. Withdrawing from the pool is also a distinct event worth tracking carefully, since it factors into how cryptocurrency transactions are taxed in ways that are easy to overlook amid the pool’s automatic rebalancing.
The takeaway
Calling this loss “impermanent” describes what’s mathematically true while funds sit in the pool — the comparison can still shift back toward zero. It says nothing about whether prices actually will move back, which is why a paper condition with a reassuring name can end a position as a very real, permanent loss.