Bitcoin BTC

Someone using the name Satoshi Nakamoto, who published the design in 2008, ran the project's early years by email, and vanished in 2011. Nobody has convincingly proved who they were, and the roughly one million coins in wallets linked to them have never moved. It is one of the stranger facts about the world's largest cryptocurrency: its founder walked away from both the fortune and the credit.

Around 20 million exist today, of a maximum of 21 million that will ever exist. The last fraction will not be mined until around 2140, because the rate of new coins halves every four years. Millions are widely assumed lost for good: keys thrown out, passwords forgotten, owners gone. Scarcity is the point of the design, and lost coins only add to it.

Mining is how transactions get confirmed and how new coins enter circulation. Computers around the world race to solve a puzzle roughly every ten minutes; the winner adds the next page to the ledger and is paid in new bitcoin for doing it. The puzzle has no value in itself. It exists to make rewriting the record so expensive that cheating never pays for itself.

Every four years or so, the reward miners earn is cut in half. It is the mechanism that enforces the 21 million cap: the flow of new coins slows on a schedule everyone can see, until it stops entirely. Halvings get talked about endlessly because past ones came before big price moves. Whether that pattern means anything is a debate, not a fact, and we treat it as one.

Yes. Owning it, buying it and selling it are all legal. It is not legal tender, which means nobody has to accept it as payment, and the industry around it is only partly regulated. Firms serving UK customers must register with the FCA for anti-money-laundering checks, and promoting crypto to UK consumers is a regulated activity, but the coins themselves sit outside most financial rules.

No. A bitcoin divides into 100 million units called satoshis, and exchanges will sell you almost any fraction of one. The whole-coin price is what makes headlines, but the size of your purchase is your decision, not something the coin's price decides for you. Most people who own bitcoin own a fraction of one.

Two choices. Leave the coins with the exchange, which is convenient and means trusting the exchange with them. Or withdraw them to a wallet you control, which means holding a secret key and being entirely responsible for it: lose the key and the coins are gone, with no reset button and nobody to ring. People have lost money both ways, and which trade-off suits you is a genuinely personal question.

Because nothing anchors it. A share has earnings behind it, a bond pays interest, a currency has an economy; bitcoin's price is purely what the next buyer will pay. Sentiment, regulation and large holders moving coins can all swing it violently, and regularly do. It has lost half its value more than once, and it has also multiplied many times over. That range is the honest answer.

There is no switch. The network runs on thousands of computers across dozens of countries, and stopping it would mean stopping all of them at once. What governments can and do regulate is the edges: the exchanges where ordinary money flows in and out, which is where real-world pressure actually gets applied. The record itself has run without interruption since 2009.

No. The £85,000 FSCS protection that covers a failed bank does not cover crypto, whoever you bought it from. If the platform holding your coins goes under, you become one creditor among many. This is the single biggest practical difference between money in a bank and bitcoin on an exchange, and it is why the standard advice is never to keep more there than you could stand to lose.

Real and large. Mining consumes roughly as much electricity as a mid-sized country, which is either an outrage or the honest cost of running a financial system with no trusted middleman, depending on who you ask. Two things are true at once: the design makes heavy energy use deliberate rather than accidental, and miners chase the cheapest power available, which increasingly means stranded or renewable sources. Neither fact settles the argument.