[KK7NIL]

Crypto trading takes place on exchanges, not the blockchain though?

[scrlk]

In crypto, you have centralised (e.g. Coinbase) and decentralised exchanges (e.g. Uniswap). Decentralised exchanges operate onchain via smart contracts.

This article from a16z explains the mechanics of reordering transactions for profit (MEV): https://a16zcrypto.com/posts/article/mev-explained/