Most trades on Binance or Coinbase don’t go directly on the blockchain. When you deposit crypto into the exchange, it goes into their wallet, and your account balance updates inside their system, not on-chain. When you buy or sell, it’s just numbers changing in the exchange’s database — no blockchain transaction happens at that point. Only when you withdraw your crypto to your own wallet does the exchange send it on-chain, and that’s when it appears on the blockchain. This system keeps trading fast and cheap, but it also means you have to trust the exchange to hold your funds safely. That’s why audits and proof of reserves are so important.