Uniswap

Swap Execution

Slippage tolerance sets max acceptable price change — 0.5% for stablecoins, 1-3% for volatile pairs, higher for low liquidity tokens
"Price impact" and "slippage" are different — impact is immediate effect of your trade size, slippage is protection against price movement
High price impact (>2%) means you're moving the market — split large trades or use limit orders on Uniswap X
Transaction deadline prevents stale swaps — 20-30 minutes default is usually fine, but pending tx beyond deadline will fail

Public swaps on Uniswap are visible in mempool before execution — bots can sandwich your trade
Use MEV protection: swap through Uniswap wallet (built-in protection), or connect via Flashbots Protect RPC
Signs of sandwich: execution price worse than quoted, with suspicious buy before and sell after your tx
Uniswap X routes through private order flow — significantly reduces MEV extraction

First swap of any token requires approval transaction — this is normal, costs gas, and happens once per token per spender
"Infinite approval" is the default — convenient but risky if Uniswap router is ever compromised
Check and revoke old approvals at revoke.cash — approvals persist forever until explicitly revoked
Approval transaction can succeed while swap fails — user pays gas for approval but swap reverts on slippage

Anyone can create a token with any name and symbol — "USDC" on Uniswap might not be real USDC
Always verify token contract address on CoinGecko, CoinMarketCap, or project's official site
Warning signs: no liquidity, recently created, honeypot (can buy but not sell), tax on transfer
Uniswap shows warning for unverified tokens — don't ignore it, especially for tokens you found via links

Impermanent loss is real and permanent when you withdraw — LPs lose vs just holding when prices diverge
V3 concentrated liquidity amplifies both gains and losses — narrow range means more fees but higher IL risk
Out-of-range positions earn zero fees — price moves outside your range, you hold 100% of the depreciating asset
V2 is simpler: full range, less management, but less capital efficient — consider for volatile pairs you want to forget

Narrower range = more fees per dollar but more rebalancing — only worth it if you actively manage
Gas costs to adjust positions add up — each add/remove liquidity is a transaction
"Collect fees" is separate from "remove liquidity" — uncollected fees stay in the position
NFT represents your V3 position — losing the NFT means losing access to the liquidity

Approve + swap is two transactions on first use — budget gas for both
L2s (Arbitrum, Base, Optimism) have Uniswap with 10-50x lower fees — same interface, same liquidity depth
Swapping during low gas periods (weekends, UTC night) saves significantly on mainnet
Failed transactions still cost gas — simulate first if unsure about slippage or liquidity

"Insufficient liquidity" — try smaller amount or different route
"Slippage exceeded" — price moved during pending period, increase slippage or retry
"Transfer failed" — token has transfer tax or restrictions, may be a scam token
"Deadline exceeded" — transaction was pending too long, just retry
"Approve first" — need to approve token before swap, this is normal

Uniswap X uses off-chain orders filled by market makers — no gas if order isn't filled
Limit orders let you set target price — order sits until price is reached or expires
Partial fills possible — large orders may fill incrementally
Check order status in the app — pending orders can be cancelled