The short version
- Bitcoin is a digital asset recorded on a public blockchain that no company or government controls.
- Supply is capped at 21 million coins; new coins are released through mining, and the reward halves roughly every four years.
- It pays no income and its price swings widely, so it behaves very differently from a share or a savings account.
What is Bitcoin, in one line? It is a form of digital money that runs on a public network rather than through a bank. Launched in 2009, it lets people send value to each other over the internet without a middleman, with the record of who owns what kept on a shared ledger called a blockchain. Its price in dollars is set by whatever buyers and sellers agree, which is why it moves so much.
How the network works
Thousands of computers around the world run Bitcoin software and keep a full copy of the ledger. When you send bitcoin, your wallet signs the transaction and broadcasts it. Miners collect pending transactions into a block and compete to solve a computational puzzle. The first to succeed adds the block, and other computers check that every transaction in it follows the rules. A new block is found about every ten minutes on average.
This competition, called proof of work, is what makes rewriting history so expensive: an attacker would need to redo the work faster than the rest of the network combined.
A fixed supply and the halving
Bitcoin's rules cap the total supply at 21 million coins. New coins enter circulation only as rewards to the miner who adds each block, and that reward is cut in half roughly every four years, an event known as the halving. Halvings took place in 2012, 2016, 2020 and April 2024; the reward is now 3.125 BTC per block, and the next halving is expected around 2028.
To put the current rate in perspective: with blocks roughly every ten minutes, about 144 blocks are found per day, so around 144 × 3.125 = 450 new bitcoin are issued daily. After each halving that figure falls by half. Whether scarcity supports the price is debated; supply is only half the story, and demand can fall as easily as it rises.
Satoshis: you do not have to buy a whole coin
One bitcoin divides into 100 million units called satoshis (sats). You can buy any fraction. As an illustration, if bitcoin were priced at $62,500, then $50 would buy 0.0008 BTC, or 80,000 satoshis. A high price per coin does not by itself make bitcoin "expensive" or "cheap"; the percentage change is what matters to your money.
Transaction fees and confirmations
Each block has limited space, so transactions compete to be included. The sender attaches a fee, and miners generally pick the transactions paying the most per unit of data first. When the network is busy, fees rise; when it is quiet, a small fee may be enough. Fees depend on the size of the transaction in data terms, not on the amount of bitcoin sent, so moving a small amount can cost the same as moving a large one.
After a transaction is included in a block, every further block adds a confirmation. Many services wait for several confirmations before treating a deposit as final, which is why a transfer can take longer than ten minutes to show as available.
Ways people gain exposure
There are two broad routes. The first is buying bitcoin itself, on a platform or through a broker, and either leaving it there or moving it to your own wallet. The second, available in some countries, is buying an exchange-traded product that holds bitcoin or tracks its price, through an ordinary investment account. Such products avoid the need to manage keys, but they charge annual fees, you do not own the coins directly, and their availability and treatment for retail investors differ by country. Whichever route you consider, check who is authorised to sell it to you where you live.
Wallets and keeping bitcoin safe
Owning bitcoin means controlling the private key that can spend it. You can let a platform hold the key for you (custodial) or hold it yourself in a software or hardware wallet (self-custody), usually backed up by a recovery phrase of 12 or 24 words.
- Write the recovery phrase on paper and store it somewhere safe and offline. Never photograph it or type it into a website.
- Anyone who asks for your phrase, whatever they claim to be, is attempting theft.
- Test your backup with a small amount before storing anything significant.
- If you keep coins on a platform, check how it is regulated and how it holds client assets; see what to check before choosing a platform.
What moves the price
Bitcoin produces no earnings, pays no dividend and has no central bank behind it, so traditional valuation tools do not apply. Its price reflects demand from individuals and institutions, changes in regulation, the availability of investment products that hold it, general appetite for risk, and the flow of new supply from miners. Sharp falls have happened repeatedly in its history, followed at times by strong recoveries; neither direction is guaranteed.
If you do buy, the crypto profit calculator shows how fees on the purchase and the sale change your real result.
Bitcoin compared with shares and cash
| Bitcoin | Shares | Cash savings | |
|---|---|---|---|
| Produces income? | No | Possibly, through dividends | Yes, interest |
| Who stands behind it? | A network following open rules | A company and its profits | A bank, often with deposit protection |
| Typical price swings | Very large | Moderate to large | None in nominal terms |
| Trading hours | 24 hours, every day | Exchange sessions on weekdays | Not traded |
Many people who hold bitcoin treat it as a small, high-risk slice of a wider portfolio rather than a replacement for savings or a diversified share fund. Understanding how crypto works more broadly will help you judge where, if anywhere, it fits for you.
Common misunderstandings
- "Bitcoin is anonymous." Every transaction is public. Addresses are not labelled with names, but they can often be linked to people through platforms and analysis.
- "The halving guarantees a rise." It reduces new supply; it does not set demand.
- "I can always get my coins back." Transfers are final. There is no bank to reverse a payment made to a scammer.
Reader questions
Who controls Bitcoin?
No single person or company. Changes to the rules require broad agreement among the people who run the software, and no one can create coins outside the issuance schedule.
What happens when all 21 million bitcoin are mined?
Miners would then rely on transaction fees rather than new coins. Because the reward halves repeatedly, the last fractions are not expected to be issued for more than a century.
Is Bitcoin legal?
In many countries it is legal to own, but rules on platforms, tax and advertising vary widely, and some countries restrict it. Check the position where you live.