What is Bitcoin? A clear guide to how it works and its risks

Bitcoin went from an obscure internet experiment to an asset held by individuals, companies and funds worldwide. But many people still aren’t sure what is Bitcoin, exactly, or why anyone values it. This guide explains how it works in plain English, along with the risks that matter before you buy any.

What is Bitcoin, in simple terms?

Bitcoin is a digital currency that lets people send value directly to each other over the internet, without a bank or payment company in the middle. It was described in a 2008 white paper by a person or group using the name Satoshi Nakamoto, and the network launched in January 2009.

Unlike dollars or euros, Bitcoin isn’t issued by a government or central bank. Its rules are written into open-source software, and anyone can run that software to help keep the network going.

How does Bitcoin work?

The blockchain: a shared public ledger

Every Bitcoin transaction is recorded on the blockchain, a public ledger copied across thousands of computers (“nodes”) around the world. Transactions are grouped into blocks; each block links to the one before it, forming a chain. Changing an old record would mean redoing all the work since, which makes the history extremely hard to tamper with.

Mining and proof of work

New blocks are added by miners, who use specialized computers to solve a mathematical puzzle. The first to solve it adds the next block and earns newly created bitcoin plus transaction fees. This process, called proof of work, secures the network but uses a lot of electricity, a common criticism.

Wallets and keys

You hold bitcoin through a wallet, which stores your private keys — the secret codes that prove ownership. Whoever controls the keys controls the coins. Lose them, and the bitcoin is gone for good; there’s no password reset.

Why does Bitcoin have value?

Bitcoin has no earnings, dividends or government backing. Its value comes from what people are willing to pay, and supporters point to a few features:

• Fixed supply: there will only ever be 21 million bitcoin. New issuance halves roughly every four years, slowing supply growth.
• Decentralization: no single authority can create more or block transactions.
• Portability: it can be sent anywhere in the world, around the clock.
• Network effect: as more people, companies and funds use it, it becomes more established.

Supporters call it “digital gold,” a store of value outside the traditional financial system. Critics argue it has no intrinsic value and that its price is driven largely by speculation.

How can you own Bitcoin?

In the US, spot Bitcoin ETFs were approved in January 2024, letting investors gain exposure through ordinary brokerage accounts. Availability differs by country.

Exchange failures have cost customers billions in the past, so choose regulated platforms and understand who holds your assets.

What are the risks of Bitcoin?

Extreme volatility. Bitcoin has fallen more than 70% from its peak several times, including in 2018 and 2022. Big daily swings are normal.

No fundamental anchor. Without earnings or cash flows, there’s no agreed way to value it. Prices can fall a long way if demand fades.

Security and loss. Hacks, scams, lost keys and fraudulent “investment” schemes are common. Nobody can reverse a mistaken or fraudulent transaction.

Regulation and tax. Rules continue to evolve and vary by country. Selling or spending bitcoin can trigger tax.

Scams. Promises of guaranteed returns, “doubling” schemes and celebrity giveaways are red flags. Legitimate investments never guarantee profits.

Should Bitcoin be part of your portfolio?

That depends on your goals and your tolerance for risk. If you choose to own some:

• Make sure your emergency fund and core investments are in place first. See how to start investing.
• Treat it as a high-risk, speculative holding and keep it to a size where losing all of it wouldn’t derail your plans.
• Consider buying gradually; dollar-cost averaging spreads out the timing, though it doesn’t reduce the underlying risk.
• Learn how custody works before buying, and use reputable, regulated providers.

The bottom line

Bitcoin is a decentralized digital currency with a fixed supply, recorded on a public blockchain and secured by miners. Supporters see it as a modern store of value; skeptics see a speculative asset with no intrinsic worth. Both agree on one thing: it is extremely volatile. Understand how it works and how you’d hold it, and never invest more than you could afford to lose.

This guide is general information, not personal financial advice. Crypto-assets are high-risk and largely unregulated in some countries; you could lose all the money you invest.