when you swap an ERC token, they never leave your wallet.
You're saying that they never leave your wallet mgr tool, MetaMask for example, but they do change wallets, just like if I sell BTC and buy LTC, I still have control, but the wallets are different, even if I'm using Trezor, right?
RE: An Example How Uniswap Calculate The Price Of The Tokens and What Happens When A Swap Is Made