Let’s talk about something that sounds harmless but quietly eats profits: AMM impermanent loss. It does not scream. It does not crash your portfolio. It just sits there, smiling politely, while your gains take a slightly smaller seat than they should have. If crypto had background characters, AMM impermanent loss would be the one quietly moving money around while everyone is watching charts.
This guide breaks it down in plain English. No mystery, no noise, no pretending it is simpler than it is.
What is impermanent loss in crypto?
Impermanent loss (IL) is the opportunity cost of providing tokens to a liquidity pool instead of simply holding those same tokens in your wallet. At its core, impermanent loss is simple.
It is the difference between:
- holding your tokens in your wallet
- and putting those same tokens into a liquidity pool
If the prices move, your pool position may end up worth less than just holding. That difference is AMM impermanent loss.
It is called “impermanent” because if prices go back to where they started, the gap can shrink or disappear. But if you exit while prices are still different, it becomes very permanent, very quickly.
How does AMM impermanent loss work?
In AMMs, prices are not maintained by an order book. They are implied by a pool formula. For Uniswap v2-style pools, the core rule is the constant-product formula:
x * y = k
where x and y are token reserves. Uniswap’s docs and whitepaper describe this directly. That equation quietly runs the whole show. Instead of buyers and sellers setting prices, the pool balances itself. When the market price changes, traders step in and trade against the pool until the pool matches reality again. And that is where AMM impermanent loss begins to sneak in.
The intuition in one sentence
IL is what happens because the pool automatically sells your winner and buys your loser as prices diverge. Yes, that is it. Your best-performing asset gets trimmed. Your weaker asset gets topped up. The pool stays balanced. Your profits do not. You are not just earning fees. You are selling a bit of your upside every time the market moves.
Why it happens
Imagine you deposit two assets into a pool. One suddenly becomes more valuable. Traders rush in:
- They buy the rising asset from the pool
- They sell the weaker asset into the pool
The result:
- You now hold less of the winner
- You now hold more of the underperformer
The pool is doing its job perfectly. You, unfortunately, are now experiencing AMM impermanent loss.
The basic math for a 50/50 constant product AMM
Here is the part that looks scary but is actually friendly once you see it. If the price changes by a factor of r, for a standard 50/50 constant-product pool, the LP value relative to a passive hold is:
LP value relative to HODL = 2√r / (1 + r)
So the impermanent loss is:
IL = (2√r / (1 + r)) − 1
That number is usually negative because it measures underperformance versus holding.
What the formula means
If the relative price does not change, r = 1, so IL = 0.
If the price doubles, r = 2:
IL = 2*sqrt(2)/3 – 1 ≈ -5.72%
If the price triples, r = 3, IL ≈ -13.40%.
If the price goes up 5x, IL ≈ -25.46%.
So yes, you are still making money. But you are making less than you could have. That gap is AMM impermanent loss quietly doing its thing.
Using the formula, the underperformance for some common moves is:
- 1.25x move: about 0.62%
- 1.5x move: about 2.02%
- 2x move: about 5.72%
- 3x move: about 13.40%
- 5x move: about 25.46%
A concrete example
Suppose you deposit:
- $1,000 of ETH
- $1,000 of USDC
Total = $2,000
Assume ETH later doubles versus USDC.
If you had simply held:
- ETH becomes $2,000
- USDC stays $1,000
- total = $3,000
In the 50/50 AMM, arbitrage trades against the pool until the new reserve ratio reflects the new market price. Your LP position ends up worth:
3000 × (1 – 0.05719) ≈ $2,828.43
So you are up in dollars, but still $171.57 behind HODL. That gap is the impermanent loss.
Important nuance: IL is not always an actual net loss
People often misunderstand the term.
Impermanent loss is not the same thing as “you lost money overall.” It means your LP position underperformed a passive hold of the same assets. You might still be profitable in absolute terms if:
- Both tokens rose
- Trading fees were large
- Incentive rewards offset the underperformance
That is why LP economics are always:
Net LP result = fees + rewards − IL − gas − any other costs
Fees can offset IL, but not reliably
This is where reality steps in. Yes, you earn trading fees. That is the reward for providing liquidity.
But studies have shown something uncomfortable. In many cases, fees did not fully cover AMM impermanent loss. Some liquidity providers would have been better off doing nothing at all. So the equation becomes: fees + rewards – AMM impermanent loss
And that result is not always positive.
AMM impermanent loss vs loss versus rebalancing
There is a more technical cousin called loss versus rebalancing.
- Impermanent loss compares you to holding
- Loss versus rebalancing compares you to a smarter, constantly adjusting strategy
The key idea is the same. Markets move fast. Pools adjust slowly. Arbitrage traders take advantage. Value leaks out. That leak is what shows up as AMM impermanent loss.
What about Uniswap v3 and concentrated liquidity?
Uniswap v3 added a twist. You can now choose where your liquidity sits within a price range. Sounds great. And it is. But there is a catch. When the price moves outside your range:
- You can end up holding only one asset
- Your exposure becomes sharper
- Your risk increases
So concentrated liquidity can boost returns, but it can also amplify AMM impermanent loss if you get the timing wrong.
Does every AMM have the same IL profile?
Not at all. Different designs behave differently.
- 50/50 pools have standard impermanent loss
- weighted pools like 80/20 reduce exposure to one side
- Stable pools aim to reduce movement when assets track each other
Stablecoin pools, for example, usually experience lower AMM impermanent loss when everything behaves. But if a peg breaks, things can get ugly fast.
What determines how bad IL gets?
A few things matter a lot:
- How far prices diverge
- How the pool is designed
- How concentrated your liquidity is
- How strong are trading fees?
- How correlated the assets are
The more one asset runs away from the other, the bigger the AMM impermanent loss.
Common misconceptions
- “Impermanent loss only happens when prices fall.”
No. It happens when prices move apart in any direction. - “Fees always cover it.”
No. Sometimes they do. Sometimes they do not. - “Stable pools have no risk.”
No. They have less risk until they suddenly have a lot. - “New AMMs solved it.”
No. They improved efficiency. They did not remove AMM impermanent loss.
The honest way to think about it
Providing liquidity is not passive income in the simple sense.
You are:
- Holding two assets
- Letting a formula manage them
- Because they are trading against your liquidity, not theirs
- Earning fees for taking that risk
That is the trade. And once you see it clearly, AMM impermanent loss stops being confusing and starts being something you can actually plan around.
Conclusion: The quiet trade-off
AMM impermanent loss is not a bug. It is the price you pay for earning fees in an automated system. You give up some upside in exchange for a steady income. Sometimes that trade works beautifully. Sometimes it does not. But once you understand it, you stop chasing “easy yield.” In simple terms, you are trading some of your upside for consistency and starting to ask the only question that matters: Is the reward worth the silent cost?
