Learn › Chapter 2 of 11

Chapter 2 · What you actually own

Where Is Your Bitcoin, Really? (It's Not in Your Phone)

Prefer to watch? This chapter is also a short video (about 4½ minutes). The full text is below.

In one minute: Your bitcoin never sits in your phone or your device. It lives on a public record kept by thousands of computers, and what you own is the secret key that can move it. Either a company holds that key for you, which is easy but means you hold a promise, or you hold it yourself, which is safer from company failures but means you're responsible. This chapter helps you see which one you have.

Ask someone who owns bitcoin where it is, and they'll usually point at something: an app on their phone, or a small device in a drawer.

Neither is quite right. And understanding why is the single most useful thing in this whole guide.

Bitcoin lives on a shared record

Bitcoin is a list. A very long, very public list of who can move which amounts, kept identical on many thousands of computers around the world.

Nobody owns the list, and nobody can quietly change it. Every few minutes a new page is added, and every computer checks it.

Your bitcoin never leaves that list. It isn't "in" your phone, and it isn't "in" a device. When you send bitcoin, nothing travels. The list just records that a different key now controls it.

What you own is a key

So if the bitcoin stays on the list, what do you actually have?

A key. A secret, a very long number, that lets you move a particular amount on the list. Whoever has the key can move the bitcoin. That's the whole system.

Think of a mailbox in a public lobby:

• The address is like the slot in the front. You can share it with anyone. People use it to send you bitcoin.
• The key opens the back. Only the person holding it can take anything out.

Lose the key and nobody can open the mailbox, not even you. Hand the key to someone else and they can empty it.

You'll often hear bitcoiners say it in five words: "Not your keys, not your coins."

Two ways to hold bitcoin

Every family's bitcoin is held in one of two ways.

1. A company holds the key for you. This is what happens when you buy bitcoin on an exchange or in a money app and leave it there. You log in with a password, you see a balance, and it feels like you own bitcoin.

What you actually own is a promise. The company holds the key; your balance is their record of how much they owe you. It's like money in a bank, without the government insurance banks have.

2. You hold the key yourself. The key is created and kept by you, usually on a small device made for the job. No company is in the middle. Nobody can freeze it, lose it in a bankruptcy, or say no. This is called self-custody.

When the promise breaks

Most of the time, the promise holds. But when it doesn't, it breaks all at once, for everyone.

• 2014: Mt. Gox, then the world's biggest bitcoin exchange, stopped withdrawals and went bankrupt. About 850,000 bitcoin were missing. Customers started getting some of it back in July 2024, ten years later. ¹
• 2022: Celsius, a crypto lending company, froze all withdrawals on June 12, citing "extreme" market conditions, and filed for bankruptcy a month later. ²
• 2022: FTX, one of the largest exchanges, collapsed in November. Customers were eventually repaid, but in dollars, at November 2022 prices, when bitcoin was worth around $16,000. Anyone who'd held bitcoin there missed everything it gained after. ³

These weren't small, shady websites. Each was, at the time, a name millions of people trusted.

The honest trade-off

Holding your own key isn't automatically better for every family. It moves the risk; it doesn't remove it.

Look at the right-hand column. Every risk on it is one of the three from Chapter 1: theft, loss, and dying without a plan. That's not a coincidence.

Self-custody puts you in charge. The rest of this guide is about making sure that being in charge doesn't become the weak spot.

A common middle path: buy on an exchange, because it's easy, then move what you plan to keep onto a key you hold. That's where most families end up, and it's where the Beginner level starts.

Talk about it

1. Where is our bitcoin right now: with a company, with us, or both?
2. If it's with a company, could the one who doesn't manage it log in today? Should they be able to?
3. If it's with us, where is the key, and does the other one know?

If you're not sure of an answer, that's the point of the next chapter.

Sources