🏛️ Exchanges: Convenient, But You're Trusting a Company

It feels like owning it

Buying bitcoin on an exchange feels like owning it.

Technically, by default, you usually don't — yet.

What you actually hold

A centralized exchange lets you buy, sell, and hold bitcoin through an account — but by default, the exchange holds the private keys, not you.

What you hold is an IOU, backed by their promise to redeem it.

The word "yet" in the last screen matters: an exchange is a fine place to buy. It's the leaving-it-there part this lesson is about.

The pros

• Very easy onboarding
• Simple buying and selling
• No need to manage keys or seed phrases yourself
• Genuinely useful for active trading

Nobody self-custodies mid-trade. The tool fits the job.

The cons

Real counterparty risk. If the exchange is hacked, becomes insolvent, or freezes withdrawals, your funds can become inaccessible — sometimes permanently.

This isn't hypothetical. Well-known historical failures like Mt. Gox (2014) and FTX (2022) left users unable to recover funds, in some cases for years or at all.

Where it sits

Easier than self-custody, but you're trusting a company's solvency and security the same way you'd trust a bank —

usually without the deposit insurance a bank account would have.

That last clause is the part people skip.

Try it: Exchange risk timeline

Three collapses, three different causes. Match each one.

A hack, an insolvency, and a fraud. Three different causes with one identical outcome for customers: the withdrawal button stopped working. Documented history, not a hypothetical. Open the Exchange Risk Timeline tool →

Quick check: By default, who holds the private keys when you buy bitcoin on an exchange?

1. You do
2. The exchange, not you ✓
3. A government-appointed custodian

Your balance is a number in their database until you withdraw it to a wallet you control.

Quick check: What's the core risk of leaving bitcoin on an exchange long-term?

1. The price could fall
2. Counterparty risk — the exchange could be hacked, become insolvent, or restrict withdrawals ✓
3. Transaction fees accumulate over time

Price risk you keep either way. Counterparty risk is the one you take on voluntarily — and can remove with one withdrawal.

Next up

So what does it actually look like to hold your own keys?