47 Fun Facts About Bitcoin

Which carmaker bought $1.5 billion of bitcoin in 2021 and briefly let buyers pay for cars with it?

Tesla stopped accepting bitcoin for cars within two months, citing climate concerns over the fossil fuels burned to mine it.

What is bitcoin's first block, mined by Nakamoto in January 2009, called?

The genesis block's 50-bitcoin reward can never be spent, because the software skips that block's transactions as a special case.

Which newspaper's headline did Nakamoto embed in bitcoin's code in January 2009?

The Times headline said 'Chancellor on brink of second bailout for banks', read both as a timestamp and as a jab at unstable banking.

Who received the first bitcoin transaction, ten coins from Nakamoto in January 2009?

Hal Finney grabbed the software the day it came out; years later, almost paralysed by ALS, he was still writing code to harden bitcoin wallets.

In May 2010, what did programmer Laszlo Hanyecz buy for 10,000 bitcoins?

Laszlo Hanyecz paid 10,000 bitcoins for two Papa John's pizzas, which another forum user ordered and had delivered to his home.

What is the maximum number of bitcoins that will ever be issued?

Only 21 million bitcoins will ever exist, and coins whose private keys are lost can never be spent again, shrinking the usable supply.

What is the event called when bitcoin's block reward is cut, roughly every four years?

The halving comes every 210,000 blocks, which is why the last bitcoin is not expected to be mined until around 2140.

On average, how often is a new bitcoin block created?

Bitcoin targets one block every 10 minutes on average; the difficulty is recalibrated every 2,016 blocks, about two weeks, to hold that pace as mining power changes.

What is the smallest unit of bitcoin called?

The satoshi is one hundred-millionth of a bitcoin, and because bitcoin's price has soared, such tiny units are needed for small purchases.

Which hashing algorithm does Bitcoin use to chain its blocks?

SHA-256 links every block to the one before, so tampering with an old block would mean regenerating every block after it.

What is the consensus process by which miners compete to add blocks called?

Proof of work makes adding a block cost real computing effort, which is hard to produce but easy for everyone else to verify.

What is the special transaction called that pays a miner the block reward?

The coinbase transaction pays the miner the block reward, and every bitcoin in existence was first created through one.

What block size limit did Nakamoto impose, which later fuelled the scaling wars?

Nakamoto added the one megabyte limit in 2010, and years later fights over raising it split the community and led to rival forks.

Which 2017 upgrade aimed to support second-layer payment channels and improve scalability?

Segregated Witness (SegWit) activated in August 2017, moving signature data out of the base block to fix transaction malleability and raise effective capacity, which made payment channels practical.

Which coin split from bitcoin in August 2017 when supporters of bigger blocks forked the chain?

Bitcoin Cash split from bitcoin on 1 August 2017, and it later split again itself when Bitcoin SV broke away.

Which payments company ended bitcoin support in 2018, citing slow transactions?

Stripe said slow confirmations let bitcoin's price swing before a payment settled, leaving some payments for the 'wrong' amount.

Which 2017 ransomware attack, demanding payment in bitcoin, hit hospitals in Britain's National Health Service?

WannaCry was halted when a 22-year-old researcher in England registered a garbled web domain hidden in its code, tripping a kill switch.

Which magazine named a Japanese-American man in California, whose real name matched the pseudonym, as bitcoin's creator in 2014?

Newsweek's cover story named Dorian Nakamoto, who denied any link to bitcoin, and the story drew heavy criticism.

Which self-proclaimed Nakamoto was ruled by a London judge in 2024 not to be him?

Craig Wright had claimed for years to be Nakamoto, but the judge ruled that he had lied extensively to support the claim.

Which cryptographer proposed 'bit gold', a forerunner of bitcoin, years before Nakamoto's white paper?

Nick Szabo is often named as a Nakamoto candidate, but he has repeatedly denied being bitcoin's creator.

Which 1997 Adam Back anti-spam scheme became a direct precursor of bitcoin mining?

Adam Back's Hashcash made each email cost a little computing time, trivial for one sender but costly for spammers, and bitcoin mining runs on the same idea.

Which bitcoin-based dark-web market did the FBI shut down in October 2013?

Silk Road's founder, Ross Ulbricht, was arrested by the FBI in a San Francisco public library.

What sentence did Ross Ulbricht receive in 2015 for running the dark-web market he founded?

Two life terms, no parole, plus 40 years was Ross Ulbricht's 2015 sentence, but President Trump pardoned him in January 2025.

Mt Gox, which collapsed in 2014, was first planned as a site for trading which game's cards?

Jed McCaleb bought the Mt Gox domain for a Magic: The Gathering card-trading site, then in 2010 turned it into a bitcoin exchange and sold it the next year.

What brought down Mt Gox, the Tokyo bitcoin exchange that collapsed in 2014?

Hackers stole its bitcoins, and after Mt Gox halted withdrawals, protesters turned up outside its Tokyo offices.

Which country became the first to make bitcoin legal tender, in September 2021?

El Salvador paid people to sign up for its Chivo bitcoin wallet, yet usage stayed low and kept falling.

Which country made bitcoin legal tender alongside the CFA franc in April 2022?

The Central African Republic did so although few of its people could get online, and using any cryptocurrency needs the internet.

Which famous investor called bitcoin 'probably rat poison squared' in 2018?

Warren Buffett said so, yet he also said he would never short it.

Which social network's celebrity accounts, including Barack Obama's, were hijacked in July 2020 to push a bitcoin scam?

Twitter's hijackers tricked staff into giving them access to internal admin tools, then posted tweets promising to double any bitcoin sent.

Which SEC chair approved the first US spot bitcoin ETFs?

Gary Gensler approved them after an appeals court ruled that the SEC had not adequately explained rejecting Grayscale's bitcoin fund.

Which company put $250 million of its treasury into bitcoin in August 2020?

MicroStrategy started out selling business software, but its bitcoin buying turned its shares into a stand-in for bitcoin itself.

Which bitcoin slang term began as a forum typo in December 2013?

'Hodl' began as a typo of 'hold' in a Bitcointalk post titled 'I AM HODLING' on 18 December 2013, written during a price crash; it came to mean holding through volatility.

Where is James Howells' lost bitcoin hard drive believed to be?

A Newport landfill is where it ended up in 2013, and in 2025 a High Court judge threw out his legal claim against the council, saying it had no realistic prospect of success.

Which university's researchers estimated in 2025 that bitcoin mining uses about 0.5% of the world's electricity?

Cambridge's researchers found mining's electricity use still growing even though mining machines had become more efficient.

Which mining pool alarmed the community in 2014 by reaching 51% of the network's hashing power?

Ghash.io then promised to keep its share below 40%, because a pool with a majority of the hashing power could double-spend coins.

Why does BTC not conform to the ISO 4217 currency standard?

BT is Bhutan's country code, and under ISO 4217 a code's first two letters name a country; units with no country, like gold's XAU, start with X.

Which Austrian-school economist's The Denationalisation of Money is cited by the ECB as a root of bitcoin?

Friedrich Hayek argued in that 1976 book that governments should not hold a monopoly on issuing money and that private currencies should compete.

Which economist described bitcoin as a Ponzi scheme in 2014?

Nouriel Roubini said so in 2014, but legal scholar Eric Posner argued that a real Ponzi scheme takes fraud, calling bitcoin 'more like a collective delusion'.

In March 2025 President Trump signed an executive order establishing what?

A strategic bitcoin reserve, stocked with bitcoin the government had already seized in forfeiture cases, which the order says will not be sold.

Which US agency's 2013 guidance classed virtual-currency exchangers as money transmitters?

FinCEN's March 2013 guidance brought exchangers and administrators under the Bank Secrecy Act, so they had to follow anti-money-laundering rules.

Which US fuel pipeline's operator took its system offline and paid a bitcoin ransom after a 2021 hack?

Colonial Pipeline paid the DarkSide hackers, and the Justice Department later seized back about $2.3 million of the bitcoin.

Which Finnish developer did Nakamoto task with creating content for the bitcoin.org website?

Martti Malmi also founded the Bitcointalk forum while helping Nakamoto develop the software.

Which second-layer network routes bitcoin payments through off-chain channels?

The Lightning Network settles payments in under a minute, sometimes in milliseconds, without waiting for a new block to be mined.

Once the last bitcoin is mined, around 2140, what will miners earn for adding blocks?

Transaction fees are meant to give miners a reason to keep mining once no new coins are being created.

Which country led global bitcoin mining after China's 2021 ban pushed miners abroad?

The United States took the lead, and in Texas, where many miners moved, their growing power demand raised worries about keeping the grid reliable.

To whom did Nakamoto hand the network alert key and control of the code repository before vanishing?

Gavin Andresen had built The Bitcoin Faucet, a site that gave away free bitcoins to newcomers, before Nakamoto handed him the project's lead.

Which soft-fork upgrade, activated in November 2021, added Schnorr signatures to Bitcoin?

Taproot lets a coin keep complex spending rules hidden unless they are actually used, making such payments cheaper and more private.