Liquidity pools are the engine behind most decentralized exchanges. Instead of waiting for a buyer to meet a seller, traders swap against a pot of tokens that other users have deposited, and a formula sets the price. Understanding liquidity pools explains why prices move when you trade, where trading fees go, and what providers risk when they deposit.
The problem pools solve
A traditional exchange matches buyers and sellers in an order book. That works when professional market makers are constantly quoting prices. On early blockchains, where every order update cost money and time, it was impractical.
Automated market makers (AMMs) took a different approach: let anyone deposit tokens into a shared pool, and let a simple formula quote prices against it. Anyone can trade at any time, as long as the pool holds tokens. If you are new to exchanges in general, start with What Is a Decentralized Exchange?.
How a constant-product pool prices trades
The best-known AMM formula keeps the product of the two token reserves constant:
x × y = k
where x and y are the amounts of each token in the pool and k stays the same before and after every trade (ignoring fees).
A worked example
Imagine a pool holding 100 SOL and 10,000 USDC. The product k is 1,000,000, and the pool's price is 10,000 ÷ 100 = 100 USDC per SOL. (These are round numbers for illustration, not real prices.)
You want to buy SOL with 1,000 USDC:
USDC in the pool rises to 11,000.
To keep the product at 1,000,000, SOL in the pool must fall to 1,000,000 ÷ 11,000 ≈ 90.91.
You receive about 9.09 SOL, an average price of about 110 USDC per SOL.
The pool's quoted price was 100, but you paid about 110 on average. That difference is price impact: your trade was large relative to the pool. In a pool ten times bigger, the same trade would have moved the price far less. This is why deep liquidity matters so much, and why aggregators split large trades across pools, as we explain in How Solana Token Swaps Work.
After your trade, the pool's price is 11,000 ÷ 90.91 ≈ 121 USDC per SOL. Arbitrage traders will now sell SOL into the pool until its price lines up with the rest of the market again.
What liquidity providers get
When you deposit into a pool, you become a liquidity provider (LP). In return you receive a claim on your share of the pool, often represented by an LP token or, in newer designs, a position record.
Each trade pays a fee, a small percentage of the trade, which is added to the pool or credited to providers. Over time, fees can make providing liquidity profitable, especially in busy pools. How much you earn depends on trading volume, the fee tier and your share of the pool.
Impermanent loss, explained
Here is the catch. Because arbitrage keeps the pool's price in line with the market, the pool constantly sells the token that is rising and buys the one that is falling. As a provider, you end up with more of the weaker token and less of the stronger one than if you had simply held both.
The shortfall compared with holding is called impermanent loss. It is "impermanent" because it disappears if prices return to where they were when you deposited; if you withdraw while prices are different, it becomes a real loss compared with holding.
For a standard 50/50 constant-product pool, if one token's price changes by a factor r relative to the other, the loss versus holding is:
impermanent loss = 2√r ÷ (1 + r) − 1
Price change of one token vs the other | Value vs simply holding |
|---|---|
1.25× (+25%) | about −0.6% |
1.5× (+50%) | about −2.0% |
2× (+100%) | about −5.7% |
4× (+300%) | −20.0% |
0.5× (−50%) | about −5.7% |
Trading fees can offset impermanent loss, but there is no guarantee they will. In volatile pairs, especially new or speculative tokens, impermanent loss can easily outweigh fees.
Beyond constant product: other pool designs on Solana
Solana's exchanges use several pool designs, each with different behaviour:
Standard constant-product pools spread liquidity across all possible prices. They are simple and always available, but capital-inefficient.
Concentrated liquidity lets providers choose a price range, such as SOL between 80 and 120 USDC. Within that range, their capital works much harder and earns more fees; outside it, the position earns nothing and sits entirely in one token. Orca's Whirlpools and Raydium's concentrated pools use this model. Concentrated positions amplify impermanent loss and need active management.
Bin-based or dynamic designs, such as Meteora's DLMM, divide liquidity into discrete price bins and can adjust fees with volatility.
Stable pools use curves designed for assets that should trade near 1:1, such as two dollar stablecoins, giving very low price impact.
The risks of providing liquidity
Impermanent loss, as above.
Smart-contract risk in the pool's program.
Token risk. If one token in the pair collapses, the pool will leave you holding mostly that token. Pairing with a new or unverified token is especially dangerous.
Out-of-range positions in concentrated pools earn no fees until the price returns.
Rug pulls. In pools created for new tokens, whoever controls the LP position may be able to withdraw the liquidity. See What Are Solana Meme Coins?.
Should you provide liquidity?
Providing liquidity can make sense for people who want to earn fees on assets they intend to hold anyway, ideally in deep pools of established, correlated assets (such as two stablecoins, or SOL and a liquid-staking token). It suits those who understand impermanent loss and are prepared to monitor their positions. It is rarely a "set and forget" source of passive income, whatever the displayed APR suggests.
Conclusion
A liquidity pool is a shared reserve of tokens that prices trades with a formula. Traders get instant, always-available markets; liquidity providers earn fees in exchange for taking on impermanent loss and protocol risk. Knowing the maths, even roughly, will help you judge price impact as a trader and judge whether advertised returns are worth it as a provider.
Sources and further reading
Educational content, not financial advice. This article explains how things work; it is not a recommendation to buy, sell or hold any asset. Crypto assets are volatile and high-risk, smart contracts can fail, and you can lose all of the money you put in. Do your own research, check official sources, and never share your seed phrase. See our full disclaimer.