When you deposit two tokens into a shared trading pool, you need a claim that tracks your slice of those balances as other people trade against them. A screenshot of one ticker can hide whether you hold the vote token, a fungible share of one pair, or a unique position that only covers a price band.
Those three claims can sit in the same wallet app, and the fee you thought you earned as a depositor may already have been split between the share and the protocol. Reading "0.30 percent" on an old whitepaper page while a live quote shows a smaller LP slice is the same mix in fee clothing.
Constant-product automated market makers (AMMs) mint a fungible share of one pair and fold the swap fee into the two balances so the product of those balances can grow after volume. Later governance can point a slice of that same trader-paid fee at the protocol, which is bookkeeping inside one number.
Uniswap v2 is that design: a constant-product pair, a fungible LP token, and, after UNIfication, a 0.25 percent liquidity-provider slice of the 0.30 percent the trader still pays into the pair. How a Uniswap fill differs from a venue fill sits in Uniswap versus centralized exchanges. The v2 fact is the pair itself, and the next mechanical question is what that 0.25 percent does after it is paid.
How the 0.25 percent LP slice grows the pair
After UNIfication, the liquidity-provider slice of a classic v2 swap fee is 0.25 percent, with 0.05 percent pointed at the protocol, of the 0.30 percent the trader still pays into the pair. That LP slice is added to the pair's reserves, so the constant product k rises a little after volume, and your LP tokens are a share of that larger pair. You collect the fee as a bigger claim on the two balances.
k is the product of the two token amounts sitting in the pair. A swap still has to leave that product intact after the fee comes off the input, and the fee itself is extra inventory, which is why k can grow even while the pricing rule stays a constant product. The fill path that keeps the product in line belongs with how Uniswap works. The holder picture here is the share after that fee has already landed.
Suppose you hold 100 of 1,000 UNI-V2 tokens, a 10 percent share of a pair sitting at 8,000 UNI and 32,000 USDC. After a week of swaps that paid the trader fee into the pair, that 10 percent is still 10 percent of the supply. The pair now holds a little more of both tokens than a zero-fee world would have left, because each trade paid into the reserves. Your claim moved with the pair and stayed a share of those two balances.
In v2, fees compound automatically because they increase k, the constant product invariant, while later versions accrue fees as a claimable balance on a position. v2 folds the fee into the two balances first (source: Uniswap Docs, Fees).
Traders pay a 30-basis-point fee on trades, which goes to liquidity providers, and Uniswap v2 is a new implementation based on the same formula as v1 (source: Uniswap v2 Core whitepaper). 30 basis points is 0.30 percent, and that is still the number the trader pays into a classic v2 pair. After the protocol charge is on, 0.25 percent of that 0.30 percent is the LP slice you should expect on the share, with 0.05 percent pointed at the protocol.
The generic class of how AMMs work still uses a pool as inventory, and Uniswap v2's version of that class is the fee staying inside k. A thin pair still moves more for the same size, and folded fees raise the product of whatever inventory is already there.
You can leave the LP token sitting, and volume that hits the pair still changes what that token is worth in the two reserves. The next mechanical fact is the token itself: a fungible ERC-20 minted by that pair.
The LP token is a fungible ERC-20 share of one pair
A v2 deposit mints liquidity tokens to the provider, and those tokens are an ERC-20 share of that one pair, so any unit of that token is the same claim. Sending it sends the share, including fees already folded into the reserves.
Whenever liquidity is deposited into a pool, unique tokens known as liquidity tokens are minted and sent to the provider's address, and whenever a trade occurs, a 0.3 percent fee is charged to the transaction sender. To retrieve the underlying liquidity, plus fees accrued, the provider burns those tokens (source: Uniswap Docs, v2 pools). The mint and burn calls are operator steps. The holder fact is enough: the claim is a token you can transfer, and the pair is what the token points at.
Uniswap v2 mints fungible ERC-20 pool tokens representing a proportional share of reserves (source: Uniswap Docs, How Uniswap Works). Two v2 LP units in the same pair add like two equal coins. Two later-version range positions in the same pool can have different bands and different fee histories, so they skip that equal-unit add.
| What you hold | What it tracks | How fees show up |
|---|---|---|
| UNI in a wallet | Governance token | Fees on this pair stay with the LP share |
| v2 LP token | Fungible ERC-20 share of one pair | Fees already folded into that pair's reserves |
| Later-version range position | One range in one pool | Fees accrue on that position while the market is in range |
The table is a description of claims, and UNI and a UNI-V2 token can sit in the same wallet and still be two claims. A screenshot of a UNI balance leaves the pair unproven, and a screenshot of UNI-V2 leaves voting power unproven.
Liquidity tokens are themselves tradable, and the docs say providers may sell, transfer, or otherwise use them, which is why older DeFi designs wrapped UNI-V2, and also why a random token named like a pair can be junk. Read the pair contract before you treat a ticker as that share.
Matching the current ratio when adding to a live pair, wrapping ETH, or setting slippage on a mint are deposit steps. You only need the claim type so you treat UNI, UNI-V2, and a later-version range position as three lines.
One swap fee across the whole curve
Uniswap v2 has a single pool fee: 0.30 percent on every pair, paid by the trader into that pair, and liquidity on that pair sits across the whole price curve. A later version can list more than one fee for the same tickers, while classic v2 keeps one fee and one pair contract per token pairing on that factory.
The 0.30 percent is the swap fee the trader pays into that pair, which is the number the whitepaper and the v2 pool docs both treat as the pool's fee. After UNIfication, 0.25 percent of that 0.30 percent is the LP slice and 0.05 percent is the protocol slice where the switch is on. Read 0.30 percent on the quote as what the trader pays, then read the split as current settings.
Later versions introduced fee tiers, so the same two tokens can have a 0.05 percent pool and a 0.30 percent pool as separate venues, and still later versions let a creator set a fee in fine steps, including through extra pool code. Those are other pages, and the v2 holder fact is simpler: one fee, one pair contract per token pairing on that factory, and liquidity at every price the curve can reach.
The factory's primary purpose is to create one and only one smart contract per unique token pair, and the factory also holds the logic that can turn on the protocol charge (source: Uniswap Docs, v2 architecture). Direct ERC-20 pairs are why a DAI and USDC v2 pool can exist without routing through ETH, and they are also why junk ERC-20s can share a factory with UNI. Permissionless creation is access, and it is a filter you run yourself.
The whole-curve deposit is the tradeoff against a later band. Capital sits at prices nobody will trade, and it also sits at the price people are trading, while fees still fold into k on that full curve. A band that earns only while the market is inside it is a different claim, already named in the table above.
Read the pool fee on the review screen, and if the interface shows 0.05 percent, you are looking at a later-version venue, or at a different protocol.
The protocol-fee switch is a later cut of the same 0.30 percent
The 0.30 percent pool fee is the original v2 swap fee the trader pays. A protocol fee is a later slice of that same 0.30 percent, pointed at the protocol rather than at the LP share, and those are two cuts inside one number. Holding UNI skips a pro-rata dividend of protocol revenue.
At launch, the protocol charge defaulted to 0 and the liquidity provider fee was 0.30 percent. If the protocol charge is switched on, it becomes 0.05 percent and the liquidity provider fee becomes 0.25 percent (source: Uniswap Blog, Uniswap v2). The trader still pays 0.30 percent into the pair, and the split is bookkeeping inside that 0.30 percent, so treat 0.25 / 0.05 as current settings where the switch is on.
The whitepaper described that switch as a factory feeTo address that could be set later, and it was off at v2's birth. Governance turned protocol fees on years afterward. The official fees page can lag a live vote, so keep v2's 0.30 percent trader-paid pool fee and the protocol's later cut as two facts on the same 0.30 percent.
Proposal 100 on Tally was executed July 27, 2026, and protocol fees are now live across all v2 and v3 pools on 11 chains in that proposal text, while the same proposal activates v4 protocol fees on a subset of pools (source: Tally / Uniswap governance, proposal 100). That 11-chain sentence is the proposal's recap, and a v4-everywhere claim would be a different sentence.
How those protocol fees can burn UNI, and why a UNI balance still has no pro-rata claim on that stream, sits with the fee switch and UNI burns. TokenJar and Firepit are that page's mechanisms, and the v2 fact here is only the split: pool fee versus protocol cut.
A UNI holder who never minted the pair's LP token still skips the 0.25 percent LP slice. The LP token is the claim on that slice, and UNI is the vote token. Mixing them is how people talk themselves into a yield they do not hold.
UNI in a wallet vs the pair's LP token
UNI in a wallet is the vote token. What that balance can do as a vote sits in the UNI token. A v2 LP token is a share of one pair. Selling UNI leaves that pair untouched. Burning the LP token returns a mix of the two reserves and leaves the UNI line unspent.
You can hold UNI, swap UNI, or sit in a UNI pair's LP token, and those are three purposes. The first two skip minting UNI-V2. The third skips voting on its own. A wallet that shows both still has two balances.
BloFin has listed UNI/USDT on spot since January 15, 2024, 11:00 UTC. That listing date is a venue date, and a UNI/USDT fill on BloFin leaves a v2 LP token unminted.
Uniswap is a competing decentralized exchange (DEX). A BloFin UNI/USDT fill is a venue balance, and a v2 UNI pair is a contract on one chain, so shared ticker text is a shared label. If you wanted UNI you can sell on the venue without paying chain gas for that fill, the listed market matches that purpose. If you wanted a share of a pair's reserves, you needed the LP token, and minting that token is a different purpose.
The mix you would receive if you burned the LP token can drift as the pair's ratio moves. That drift is the cost of sitting on both sides of a product curve. Fees folded into k can offset some of that move, or fail to, depending on volume and how far the ratio ran. Extra equal to the original holding plus a coupon is a hope.
Read which token you are about to send. UNI, a UNI-V2 share, and a lookalike ticker can share a screen, and the pair address and the LP token address are the tell.
Why v2 still sits beside later versions
v2 stayed live when later versions shipped. Pairs that were created keep running, because the core contracts are a fixed matching engine. Later versions change where liquidity sits, then how pools are stored, and they leave the constant-product pair in place as an idea.
Uniswap v2, the second iteration of the Uniswap protocol, has been deployed to the Ethereum mainnet, and the launch post is dated May 18, 2020 (source: Uniswap Blog, Uniswap v2 Mainnet Launch). v1 pairs were left in place. v2 pairs were left in place when v3 shipped. You can still meet a v2 UNI pair in 2026, including older pools that never migrated.
What Uniswap is names the protocol as a permissionless AMM with live versions stacked. The v2 slice of that stack is the fungible share, the whole curve, the 0.30 percent trader-paid pool fee, and the later protocol cut that leaves 0.25 percent on the LP share.
The wider onchain-market picture sits in onchain markets on Ethereum. Uniswap's v2 factory is one permissionless route inside that picture, and a BloFin book is a different venue. Uniswap is named as a competing DEX in both places.
Other AMMs that copied the pair design are a different comparison. Uniswap versus Sushi stays on the Uniswap side of that fork, and Sushi internals are that page's problem. One sentence is enough here: a Sushi pool can look like a v2 pair because it forked the AMM, and it is still a different factory.
BloFin lists two UNI perpetuals: UNIUSDT at up to 75x, listed January 12, 2023, 10:00 UTC, and UNIUSD, an inverse contract settled in UNI, at up to 20x, listed June 27, 2025, 10:00 UTC. Neither perpetual mints a v2 LP token, and closing UNIUSDT leaves your UNI-V2 unburned.
A v2 swap still settles on a chain. On Ethereum that means ETH for gas, even when the pair is UNI and USDC. How Ethereum works is the chain picture. A failed swap still burns gas, and a confirmed swap already moved the reserves.
Deposit clicks, tick-setting, and a generic AMM class taught from scratch are different purposes, with their own screens and their own risks. The pair still fills swaps whether or not you minted a share. If you wanted the share, you wanted the LP token, and the mint lives on the interface that already asks for both tokens.
Common questions about Uniswap v2
How do I tell a UNI-V2 token from UNI in a block explorer?
Open the token contract, then match the hex: UNI is the protocol's vote token at its genesis address on that chain. A UNI-V2 token is the pair contract's own ERC-20, with a name that often looks like UNI-V2 or like the two tickers. The explorer's token page should show a pair or Uniswap V2 Pair contract, and a holder list that differs from UNI's. If the address matches UNI, you are looking at UNI, and if it matches a pair, you are looking at the share. A copied ticker in a search box leaves the contract unproven.
If I am the first person to mint a new v2 pair, do I receive every LP token that pair creates?
Uniswap v2 sends the first 1e-15 pool shares (0.000000000000001) to the zero address and keeps them locked. That lock, which is a constant 1000, or 1e-15, is 1,000 times the minimum quantity of an 18-decimal share. You receive the rest of that first mint, and the lock is dust. Later depositors mint against the live supply, which already excludes that locked slice. Expect a claim on the unlocked supply (source: Jeiwan, Programming DeFi: Uniswap V2 Part 1).
Can I combine a UNI and USDC v2 share with a UNI and USDT v2 share into one balance?
Each v2 pair mints its own ERC-20. A share of a UNI/USDC pair and a share of a UNI/USDT pair are different contracts even when both names start with UNI. Adding the two balances in a spreadsheet leaves the claims unmerged. Sending one token leaves the other pair's reserves unmoved. If a wallet shows two UNI-V2 tickers, you still have two claims, and the explorer address is what tells them apart.
If my v2 swap fails, does the pair still take 0.30 percent into k?
A reverted swap skips the fill, so it skips adding the 0.30 percent to the reserves, and k stays where it was. Treat a failed hash as a failed call, and a confirmed swap is the one whose two reserve slots moved. A revert also skips minting or burning your UNI-V2, so the share supply is unchanged.
Can I delegate Uniswap votes with a v2 LP token the way I can with UNI?
Delegation and voting read UNI balances the Governor can see. A UNI-V2 token is a share of a pair, so it skips counting as UNI for a proposal. Wrapping or farming that LP token in some other contract leaves voting power uncreated unless that other protocol explicitly issues UNI, which is a different protocol. If you wanted to vote, you needed UNI in a signing wallet, or a delegate you chose. The pair share is a different claim.
What should I check on a v2 pair review screen before I swap a UNI-looking ticker?
Read the two token addresses, the chain, and the pool fee. Classic v2 should show 0.30 percent, one pair, and addresses you already trust for those two tokens. A UNI ticker on a new pair can be a different ERC-20. The same two tickers on another chain are another pair with their own reserves. Depth is the two balances in that contract, and if any of those fields look off, you can leave. A tiny test swap is still a swap against that pair.
If I burn a UNI-V2 token, what mix comes back?
Burning the LP token returns a mix of the two reserves that sit in that pair at the burn block, including fees already folded into k. The mix follows the live ratio, so a pair that drifted while you held the share sends back more of one token and less of the other than you deposited. UNI in a separate wallet stays put, and the burn is a pair exit.
Researched and written by the BloFin Academy editorial team with AI-assisted drafting. Updated September 2026. Primary sources include the Uniswap v2 Core whitepaper, Uniswap Developers fees and v2 pool docs, the Uniswap v2 blog, and Tally proposal 100. All facts independently verified against cited documentation current as of September 2026.
This article is educational and general in nature, not financial or investment advice. Cryptocurrencies like UNI carry real risks, including price volatility, smart-contract risk in pair and router code, fake tokens in permissionless pools, and mix changes if you hold a v2 LP share. Nothing here is a recommendation to buy, sell, hold, or provide liquidity. Do your own research, and consider speaking with a licensed professional before making financial decisions. BloFin does not provide investment advice.