Crypto · Beginner · 4 min

Crypto exchanges, wallets, custody

You can explain the difference between leaving crypto on an exchange and holding it yourself, and which risks each choice brings.

Who holds the keys?

Your app shows a balance of two bitcoins. It looks just like a balance in a bank or brokerage account. But behind the number, a very different question decides your safety: who actually controls those coins?

In crypto, control means holding the private keys. This lesson explains the two basic choices, leaving coins with a platform or holding them yourself, and what can go wrong with each.

Their keys or yours

A crypto exchange is a platform where you buy, sell and often store crypto assets. A crypto wallet is software or a device that manages private keys. Investor.gov explains that wallets do not store the coins themselves. They store the private keys that control them on the blockchain.

Custody means who holds those keys.

Third-party custody. When you keep crypto on an exchange, the platform holds the keys for you. Trading is easy, and you can reset a forgotten password. But the SEC warns that if the custodian is hacked, shuts down or goes bankrupt, you may lose access to your crypto. It also advises asking whether the custodian lends out customer assets or mixes them with its own or other customers' assets.

Self-custody. You hold the keys yourself. Hot wallets run on internet-connected devices, convenient but exposed to online attacks. Cold wallets are offline, such as a dedicated device or even paper, safer from hackers but at risk of loss, damage or theft. Nobody can freeze your coins, but nobody can recover them either. The next lesson covers keys and seed phrases in detail.

Either way, protection is thin. The SEC points out that the safeguards of brokerage accounts and bank deposits, such as SIPC or deposit insurance, do not apply to accounts with crypto asset firms. In the EU, MiCA now requires authorized providers to keep client crypto separate, but it is not a compensation scheme.

Two ways to lose

Two fictional investors each hold crypto worth 10,000.

Investor A keeps it on a large exchange. One morning, withdrawals are halted. The exchange had been lending out customer coins. In the insolvency, customers wait years to recover part of their money.
Investor B keeps it in self-custody. After moving house, the paper with the seed phrase is gone, and the old phone is broken. The coins still exist on the blockchain, but nobody can ever move them again.

Both lost access for different reasons. Choosing a custody model means choosing which risk you can manage better.

Common mistakes

Assuming an exchange balance is protected like a bank deposit. It usually is not.
Keeping everything on one platform. A single failure hits all of it.
Storing seed phrases online. Screenshots and cloud notes invite theft.
Not checking whether a provider lends out client assets. It changes the risk.

The takeaway

On an exchange, someone else holds your keys. In self-custody, you do. Either way, crypto lacks the protection of bank deposits or brokerage accounts.

Check yourself

Quick quiz

4 questions. Instant feedback, nothing is saved.

1Tap the option in which a platform failure can cost you your coins.

Tap the chart.

The SEC warns that if a third-party custodian is hacked, shuts down or goes bankrupt, you may lose access to your crypto assets.
2What does a crypto wallet actually store?

Investor.gov: wallets do not store crypto assets, they store the private keys.
3Are crypto holdings at an exchange protected like bank deposits or brokerage accounts?

The SEC notes that there are no such protections for accounts placed with crypto asset entities.
4What should you ask a crypto custodian, according to the SEC?

Lending out (rehypothecation) and mixing customer assets increase the risk of losses if the firm fails.

of 4 correct.