Exchange Custody vs. Self-Custody
Keeping coins on an exchange means handing them to someone else to look after; keeping them in your own wallet means their safety is up to you.
Risk warning: forex, CFDs, options, futures and crypto assets usually involve leverage or high volatility, and you can lose more than you put in. This lesson only teaches the concepts; all numbers are for illustration and are not investment advice.
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Text version · Crypto Basics, lesson 3: “Exchange Custody vs. Self-Custody”
Keeping coins on an exchange means handing them to someone else to look after; keeping them in your own wallet means their safety is up to you.
Held by an exchange: someone else holds the keys
Once your coins are on an exchange, it holds the private key and you get a number on its books. Trading is easy, but if the exchange runs into trouble, you're caught up in it.
Self-custody: you hold the keys
self-custody: you hold the private key, for example in an offline cold wallet. An exchange collapse can't touch it, but guarding against loss and theft is up to you.
Split it up: don't put all your eggs in one basket
Common practice: keep a small amount you'll trade soon on an exchange and long-term holdings in a cold wallet. Wherever you keep them, turn on two-factor authentication, use the official website and watch out for phishing sites.
Key takeaways
- Exchange custody: easy to trade, but the exchange holds the private keys (not your keys, not your coins).
- Self-custody: you hold the private keys, so an exchange collapse can't touch you, but you must guard against loss and theft yourself.
- A common approach: keep a small amount on the exchange for trading and long-term holdings in a self-custody cold wallet.
Try it yourself
You can do these exercises in this lesson's interactive simulation:
- Keep 50% / 50% and click "Exchange hacked / collapses": which side's money can you still use?
- Click "You lost your seed phrase": which side is in trouble this time?
- Click "Want to sell right now" and compare how many steps each side takes.
- Set the exchange share to 20%, then trigger each of the four events in turn and see what "Total still available" is each time.
Quiz and explanations
- 1. What does "Not your keys, not your coins" mean?
- Answer: If you don't hold the private keys, the coins aren't fully yours.With exchange custody, what you own is just a claim against the exchange.
- 2. If an exchange collapses, which kind of holding is safer?
- Answer: A self-custody wallet.Self-custodied assets aren't affected by the exchange going bankrupt.
- 3. You have $10,000 of crypto: 30% on an exchange and 70% in a cold wallet. The exchange collapses and freezes assets. How much can you still use?
- Answer: $7,000.The 70% in the cold wallet, $7,000, is unaffected; the $3,000 on the exchange has to wait for the bankruptcy process.
Terms in this lesson
- cold wallet (Cold Wallet): A wallet that stores private keys offline, which makes it more secure.
- exchange (Exchange): A central marketplace that matches buy and sell orders, such as the NYSE or NASDAQ.
- private key (Private Key): The one credential that can move the assets in a wallet; whoever holds the private key controls the assets.
- seed phrase (Seed Phrase): A backup of your private key as a list of words; leaking it means handing over all your assets.
- self-custody (Self-Custody): Keeping your own private keys (for example in a hardware wallet) instead of relying on an exchange.