99 Fun Facts About Cryptocurrency

What is the pseudonym used by the creator or creators of Bitcoin?

Whoever it was went silent in April 2011 and has never moved the roughly one million coins mined in the first year.

In what year was the Bitcoin white paper, 'Bitcoin: A Peer-to-Peer Electronic Cash System,' published?

It was posted to a cryptography mailing list on Halloween and was ignored by academics, who argued the design could not work; the network went live that January.

What is the term for any cryptocurrency other than Bitcoin?

It is short for 'alternative coin'; the Wall Street Journal called them 'alternative versions of Bitcoin', which remains the template most of them copy.

Which 2011 cryptocurrency by Charlie Lee is nicknamed the 'silver to Bitcoin's gold'?

Litecoin, released by Charlie Lee in October 2011, copied Bitcoin's code with faster 2.5-minute blocks and the Scrypt hashing algorithm, which was briefly resistant to specialised mining chips.

On a proof-of-work blockchain, what is adding blocks and earning new coins called?

Purpose-built machines race to find a nonce that hashes below the difficulty target; the winner's block reward is currently 3.125 bitcoin.

What is the very first entry in a blockchain, Bitcoin's dating from 3 January 2009, called?

The genesis block, Block 0, was mined by Satoshi on 3 January 2009 with that day's Times headline about a second bank bailout embedded in it, a timestamp and a pointed comment in one.

Which key must be kept secret because whoever holds it can spend a wallet's funds?

The private key is the secret that signs transactions, so anyone holding it can spend the wallet's funds; lose it and the coins are unrecoverable, hence 'not your keys, not your coins'.

Which type of key can be handed out freely so that others can send you cryptocurrency?

The public key can be shared openly; a wallet address is derived from it, while the matching private key signs outgoing transactions and must never be shared.

Which kind of cryptocurrency is pegged to a national currency such as the US dollar?

Stablecoins such as Tether and USDC peg to the dollar with reserves; the algorithmic kind is riskier, and TerraUSD's collapse in 2022 wiped out about $40 billion.

Which US agency, created in 1934, has claimed jurisdiction over many crypto tokens?

The SEC, founded in 1934 after the 1929 crash, applies the 1946 Howey test to tokens, asking whether buyers invested in a common enterprise expecting profits from others' efforts; a sister agency treats bitcoin as a commodity.

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

Hal Finney, the cypherpunk who built the reusable proof-of-work system RPOW in 2004, received ten bitcoin from Satoshi on 12 January 2009, a day after tweeting 'Running bitcoin'.

What is the term for a blockchain protocol change that makes old versions incompatible?

A hard fork changes the rules so every node must upgrade or be left on the old chain; a soft fork, by contrast, tightens rules in a way old software still accepts.

What is the primary purpose of a smart contract on a blockchain?

Its purpose is to run agreed terms automatically, as code rather than a legal document; Nick Szabo coined the term in the 1990s, long before there was a blockchain to run one on.

Which country was the first to adopt Bitcoin as legal tender?

El Salvador's Bitcoin Law, pushed by President Nayib Bukele, took effect on 7 September 2021, making bitcoin legal tender alongside the US dollar; acceptance was made voluntary in January 2025 under an IMF loan deal.

What is the roughly four-yearly event that cuts Bitcoin's block reward called?

The halving happens every 210,000 blocks, with the last coin expected around 2140; the 2024 event took the block reward from 6.25 to 3.125 coins.

What kind of token certifies ownership of digital art on a blockchain?

A non-fungible token (NFT) is a unique on-chain record that usually points to a file rather than containing it; Beeple's 'Everydays' NFT sold for $69 million at Christie's in March 2021.

What consensus mechanism is used by Bitcoin to validate transactions and secure its network?

Miners burn electricity hunting for a nonce that hashes below the difficulty target; the idea was borrowed from a 1997 anti-spam scheme by Adam Back.

Which programmer, then 19, first proposed Ethereum in a 2013 white paper?

Gavin Wood, Charles Hoskinson, Anthony Di Iorio and Joseph Lubin joined as co-founders; the name came from a list of science-fiction elements on Wikipedia.

What is the term for crypto storage that stays connected to the internet, handy but more exposed to hackers?

A hot wallet keeps its keys on an internet-connected device such as an exchange account or phone app; standard advice is to hold only spending money in one and the rest offline.

Which company, founded in Paris in 2014, makes the Nano line of hardware wallets?

Ledger, founded in Paris in 2014, sells the Nano S and Nano X hardware wallets, which keep private keys in a secure chip offline; its 2020 breach leaked customer contact data, not keys.

Which attack did Satoshi's white paper set out to solve without a trusted third party?

Double-spending, using the same coins twice, was the core problem digital cash had to solve; Bitcoin's white paper answers it with a public ledger where the network agrees which conflicting transaction came first.

What is 'DeFi' an abbreviation for in the cryptocurrency world?

DeFi stands for Decentralized Finance: lending, exchanges and derivatives run as code on permissionless chains with no bank in the middle; the boom took off with the 2020 'DeFi summer'.

After a 2014 crowdfunding sale, in which year did the Ethereum network go live?

Its creator picked the name after browsing a list of fictional elements on Wikipedia; the crowdsale had raised about $18 million in bitcoin.

On Ethereum, transaction fees are priced in a unit named after what?

Ethereum fees are measured in gas, each operation costing a set amount; since the August 2021 London upgrade (EIP-1559) the base portion of every fee is burned rather than paid to validators.

Which year saw the first recorded commercial transaction using Bitcoin, famously for two pizzas?

On 22 May 2010 Laszlo Hanyecz paid 10,000 bitcoin for two Papa John's pizzas, the first recorded commercial purchase with bitcoin; the date is now marked as Bitcoin Pizza Day.

What is the maximum supply of Bitcoin that can ever be mined?

Just 21 million can ever exist; the last is expected around 2140, after which miners live on fees alone, and a few million are already thought lost forever.

What is the term for a blockchain's ability to handle an increasing number of transactions?

Scalability is the capacity to process more transactions as demand grows; Bitcoin's base layer handles roughly 3 to 7 transactions per second, which is why Lightning and the block-size wars exist.

What is an 'ICO' in the context of cryptocurrency funding?

An Initial Coin Offering sells a new token to fund a project; the 2017 boom raised billions on little more than white papers, and regulators later ruled many tokens were unregistered securities.

Which of these is a digital currency proposed by Nick Szabo in 1998, considered a precursor to Bitcoin?

Bit Gold, designed by Nick Szabo in 1998 but never built, chained proof-of-work puzzles so closely to Bitcoin's later design that it made Szabo a perennial Satoshi suspect, which he has denied.

What attack did Bitcoin Gold suffer in 2018, letting thieves reverse exchange deposits?

A 51% attack needs a majority of a chain's hashing power; Bitcoin Gold suffered one in May 2018 that reversed about $18 million of exchange deposits, and two more in January 2020.

Which bitcoin-only dark-web marketplace was shut by the FBI in 2013?

Silk Road founder Ross Ulbricht was arrested in San Francisco in October 2013; the FBI seized the site and the US Marshals later auctioned about 30,000 of its bitcoins, and Ulbricht was sentenced to life in 2015.

Which 2011 bitcoin fork runs a decentralised domain-name system with its own '.bit' domain?

Like bitcoin it has a hard supply cap; the '.bit' domain sits outside ICANN and was pitched as censorship-resistant.

In a cryptocurrency network, what is a 'node'?

Anyone can run one; a full node keeps its own copy of the entire chain and checks every block against the rules rather than trusting anyone else.

How are validators chosen under a proof-of-stake system?

Under proof of stake, validators are chosen in proportion to the coins they lock up as a deposit; misbehaving validators can have that stake 'slashed', doing the job wasted electricity does under proof of work.

Which Tokyo exchange handled over 70% of all bitcoin trades before collapsing in 2014 with huge losses of coins?

Mt. Gox, based in Tokyo, filed for bankruptcy in February 2014 after losing about 850,000 bitcoin; the name stood for 'Magic: The Gathering Online eXchange', the site's original purpose.

What is a 'fork' in a blockchain?

A fork is a split in the chain's history: Bitcoin Cash split from Bitcoin in 2017 over block size, and Ethereum Classic is the chain that refused to reverse the 2016 DAO hack.

Which early digital cash technology from the 1980s was developed by David Chaum?

Ecash used David Chaum's blind signatures, letting a bank sign a coin without seeing it; his company DigiCash ran it through Mark Twain Bank in St. Louis from 1995 before going bankrupt in 1998.

What does the abbreviation 'DLT' stand for?

Distributed Ledger Technology means every participant holds a synchronised copy of the same data with no central administrator; a blockchain is one design of distributed ledger, not the only one.

Which figure is calculated by multiplying a coin's price by the number of coins in circulation?

Market capitalisation is price multiplied by circulating supply; Bitcoin's share of the combined total across all coins, which traders call 'dominance', stayed above half for most of the 2010s.

A token is 'fungible' when what is true of it?

A fungible token is one where any unit can swap for any other, as one dollar or one bitcoin is as good as the next; an NFT is deliberately the opposite.

What is 'yield farming' in DeFi?

Also called liquidity provision, it took off in 2020 when Compound began paying its own token to lenders and borrowers; the returns come with smart-contract risk.

Which meme coin did Billy Markus and Jackson Palmer launch in December 2013?

Dogecoin was built by Billy Markus and Jackson Palmer in December 2013 to mock crypto speculation, only to become a top-ten coin by market value in 2021 on the back of social-media pumps.

Which 1997 anti-spam scheme by Adam Back supplied the proof-of-work idea that Bitcoin later built on?

It made a sender's computer do a small puzzle per email to make bulk spam expensive; Satoshi cited it in the Bitcoin white paper.

What does a cryptographic hash function do with its input?

A hash function produces a fixed-length fingerprint of any input; change one character and the output changes completely, which is what chains blocks together and makes tampering obvious.

What is 'Web3' often used to describe in the context of cryptocurrency and blockchain?

Web3 describes a decentralised web built on blockchains, with users holding their own data and tokens; the term dates from 2014 and became a venture-capital buzzword in 2021, which critics call a rebrand of crypto speculation.

What is a government-issued currency whose value rests on decree rather than metal reserves called?

Fiat money's value rests on government decree and public trust rather than a vault of metal; the US cut the dollar's last tie to gold in 1971.

Which US regulator, created in 1974, polices derivatives and has claimed bitcoin as its own turf?

The CFTC, created in 1974, polices derivatives and treats bitcoin as a commodity; its turf war with the SEC over which agency owns crypto has run for a decade.

Which kind of token represents an investment stake in an underlying asset, like a share?

A security token represents an investment stake in an underlying asset and is regulated like a share; its sales are STOs, a regulated cousin of the ICO, which utility, governance and payment tokens are designed to avoid.

What was Ethereum's September 2022 upgrade that dropped proof-of-work called?

The Merge, on 15 September 2022, fused Ethereum's original chain with the Beacon Chain that had run proof of stake in parallel since December 2020; validators replaced miners overnight.

Which quantitative trading firm did Sam Bankman-Fried co-found in 2017, before FTX?

Alameda Research, co-founded by Sam Bankman-Fried in 2017, was about 90 percent owned by him by 2021; its habit of borrowing FTX customer deposits is what brought both companies down in November 2022.

In which country was the FTX exchange headquartered when it collapsed in 2022?

FTX was headquartered in Nassau, The Bahamas, from 2021, though incorporated in Antigua and Barbuda; Sam Bankman-Fried was arrested there in December 2022 and extradited to the US.

Who founded Binance in 2017?

Changpeng Zhao, known as CZ, founded Binance in July 2017 after stints at Bloomberg and OKCoin; he stepped down as CEO in November 2023 after pleading guilty to US anti-money-laundering charges.

How big was Binance's November 2023 fine for breaking US anti-money-laundering rules?

Binance paid $4.3 billion; its founder pleaded guilty the same day and stepped down as CEO, and the exchange, which drifted from China to Japan to Malta, has no official headquarters at all.

Which former Airbnb engineer founded Coinbase in 2012?

Brian Armstrong, an ex-Airbnb engineer, founded Coinbase in 2012 with a $150,000 cheque from Y Combinator; ex-Goldman trader Fred Ehrsam joined as co-founder, and the name comes from the transaction that mints new coins.

Coinbase went public in April 2021 via a direct listing on which exchange?

Coinbase listed directly on Nasdaq on 14 April 2021 under the ticker COIN; a reference price of $250 a share valued it at about $47 billion, the first major crypto firm on a US stock market.

Under what name was Tether first announced in July 2014?

Tether was announced as Realcoin in July 2014 by Brock Pierce, Reeve Collins and Craig Sellars and renamed that November; it ran on Bitcoin's Omni Layer, and sister exchange Bitfinex began trading it in January 2015.

Which privacy coin hides the sender among decoy outputs using ring signatures?

Monero, launched in April 2014 from the 2013 CryptoNote white paper by the pseudonymous Nicolas van Saberhagen, hides senders with ring signatures; its RandomX mining algorithm is designed to keep specialised chips out.

Cardano's own cryptocurrency is named after which English mathematician?

Cardano's currency ADA honours Ada Lovelace, the 19th-century English mathematician often called the first computer programmer; the platform itself honours Gerolamo Cardano, and its eras are named Byron, Shelley, Goguen, Basho and Voltaire.

Which blockchain was founded in 2018 by Toly Yakovenko and Raj Gokal?

Solana, founded in 2018 by Anatoly 'Toly' Yakovenko and Raj Gokal, produced its first block on 16 March 2020 and rode the 2021 NFT boom as a cheaper rival to Ethereum despite a string of network outages.

Which Ethereum co-founder created Polkadot, the chain that links 'parachains' together?

Gavin Wood, Ethereum's first CTO, published the Polkadot white paper in October 2016; its parachain slots only went live in December 2021 after years of auctions and testing.

Roughly how much ether was drained from The DAO in the June 2016 attack?

The attacker drained about 3.6 million ether, roughly a third of the 11.5 million that investors had committed, worth around $50 million at the time; the fallout split Ethereum into two chains.

What kind of flaw did the attacker exploit to drain 3.6 million Ether from The DAO on Ethereum in 2016?

A recursive call bug, now called a re-entrancy attack, let the contract be asked for a withdrawal again before it had updated the balance from the last one.

Bitcoin Cash split in November 2018 into BCH and a rival chain called 'Bitcoin' what?

Bitcoin SV, short for 'Satoshi Vision', was the camp led by Craig Wright and billionaire Calvin Ayre that wanted 128 MB blocks; the hash war split Bitcoin Cash on 15 November 2018.

In which month and year was Segregated Witness activated on Bitcoin?

Segregated Witness activated on 24 August 2017 at block 481,824; it moved signature data out of the main block to fix transaction malleability and fit more transactions, all as a soft fork old software still accepted.

Who co-wrote the 2015 Lightning Network white paper with Thaddeus Dryja?

Joseph Poon co-wrote the Lightning Network paper with Thaddeus Dryja in 2015, describing payment channels where two parties trade off-chain as often as they like and settle only the final balance on the blockchain.

Which November 2021 Bitcoin soft fork added support for Schnorr signatures?

Taproot activated on 14 November 2021 at block 709,632, adding Schnorr signatures that let multi-signature spends look like ordinary ones; like SegWit before it, it was a soft fork so old nodes kept working.

Where was Terraform Labs founder Do Kwon arrested in March 2023 with forged travel papers?

Do Kwon was arrested in Montenegro on 23 March 2023 at Podgorica airport, trying to fly to Dubai on falsified Costa Rican documents, ten months after his TerraUSD and LUNA tokens collapsed.

Which crypto lender went bankrupt in July 2022, an insider calling it 'very ponzi like'?

Celsius Network filed for bankruptcy on 13 July 2022 after freezing withdrawals; it emerged in January 2024 by handing creditors its assets, including the new mining company Ionic Digital, and then wound itself down.

How many bitcoins were stolen from the Bitfinex exchange in August 2016?

Hackers took 119,756 bitcoin from Bitfinex on 2 August 2016, worth about $72 million then; the haul was valued at $3.6 billion when a New York couple, Ilya Lichtenstein and Heather Morgan, were charged with laundering it in 2022.

The Ronin sidechain, drained of roughly $620M in 2022, was built for which game?

Axie Infinity's Ronin sidechain lost about $620 million in ether and USDC in March 2022, a theft pinned on North Korea's Lazarus Group; the game's axolotl-like pets had sold for hundreds of dollars each at the 2021 peak.

What did the hackers behind the August 2021 Poly Network exploit do with the funds?

The Poly Network hacker returned nearly all of the roughly $610 million within two weeks; the company took to calling the attacker 'Mr. White Hat' and offered a $500,000 bounty, a framing that annoyed security researchers.

Which company is behind the Bored Ape Yacht Club NFT collection?

Yuga Labs launched the Bored Ape Yacht Club in April 2021 and was valued at $4 billion in a March 2022 funding round, on the back of celebrity owners and a members-only club pitch.

Former Siemens engineer Hayden Adams created which decentralised exchange in 2018?

Uniswap launched in November 2018, built by Hayden Adams after Siemens laid him off and a friend pointed him to a Vitalik Buterin post on automated market makers; it lets people trade from their wallets with no order book.

Chainlink, co-founded by Sergey Nazarov in 2017, is a decentralised network of what?

Chainlink's oracles ferry tamper-proof real-world data such as prices and weather onto the chain, since a smart contract cannot look outside its own blockchain; Sergey Nazarov and Steve Ellis launched it in 2017.

Which proof-of-space blockchain did BitTorrent creator Bram Cohen co-found in 2017?

Chia, founded by BitTorrent creator Bram Cohen in 2017, has 'farmers' fill hard drives with pre-computed plots instead of burning electricity; a companion proof-of-time step keeps the chain ticking between blocks.

Which Ethereum mixing service was blacklisted by the US Treasury's OFAC in August 2022?

Tornado Cash was sanctioned by OFAC on 8 August 2022; developer Alexey Pertsev was arrested in Amsterdam two days later, and in November 2024 the Fifth Circuit ruled its immutable smart contracts are not property OFAC can sanction.

Which exchange was founded in 2014 by Cameron and Tyler Winklevoss?

Gemini, founded by Cameron and Tyler Winklevoss in 2014, went live in October 2015 with a limited-purpose trust charter from New York's financial regulator; the twins were famous from their Facebook lawsuit.

Which San Francisco exchange, founded in 2011, is legally named Payward, Inc.?

Co-founder Jesse Powell had been consulting for the troubled Tokyo exchange Mt. Gox when he decided the industry needed a more professional alternative.

QuadrigaCX's founder died in which country in 2018, taking its wallet passwords with him?

Gerald Cotten, 30, died in Jaipur, India, in December 2018 while on honeymoon; customers' lawyers asked for his body to be exhumed, and Ontario regulators concluded in 2020 that QuadrigaCX had been a fraud all along.

Ruja Ignatova, the 'Cryptoqueen' who vanished in 2017, ran which fraudulent scheme?

OneCoin, sold by Ruja Ignatova from 2014, never had a real blockchain; she vanished in October 2017 after a secret US warrant was issued, and the FBI added her to its Ten Most Wanted list in 2022.

Facebook's Diem digital currency project was first unveiled under what name?

Facebook unveiled Libra in June 2019; regulators on both sides of the Atlantic savaged the plan, it was renamed Diem in December 2020, and the assets were sold to Silvergate Bank in January 2022.

Ripple Labs was founded in 2012 under what original name?

Ripple Labs began in 2012 as OpenCoin and took the Ripple name in 2013; its XRP token was pre-mined with 100 billion units, and it spent 2020 to 2025 fighting the SEC over whether selling them was a securities offering.

Which co-founder of Ripple left to launch the Stellar network in 2014?

Jed McCaleb, who had built Mt. Gox before co-founding Ripple, left in 2013 and launched Stellar in 2014; Stellar settles by quorum consensus rather than mining.

Which 2012 coin, from a paper by Sunny King, was the first to use proof-of-stake?

Peercoin, launched in August 2012 from Sunny King and Scott Nadal's paper, kept proof-of-work alongside proof-of-stake and used 'coin age', coins held multiplied by time held, to pick who mints the next block.

Bitmain's Antminer rigs are built around which kind of single-purpose chip?

An ASIC is a chip built to do one job, here SHA-256 hashing; Bitmain's first model, the 2013 Antminer S1, managed about 180 gigahashes a second, and its AntPool became one of the largest mining pools.

Which statically typed language is the main one for writing Ethereum smart contracts?

Solidity, proposed by Gavin Wood in 2014 and developed under Christian Reitwiessner, compiles to bytecode for the Ethereum Virtual Machine; its syntax borrows from JavaScript and C++.

What is the smallest unit of ether, in which account balances are stored on-chain?

Wei is the smallest unit of ether, a quintillion (10^18) of them making one ether; gas prices are quoted in gwei, a billion wei, which is why fees read as numbers like 20 or 30.

Which Ethereum token standard, led by William Entriken in 2018, covers unique tokens?

ERC-721, finalised in 2018 with William Entriken as lead author, defines non-fungible tokens with unique IDs; it was written as CryptoKitties clogged the network, and Bored Apes and most blue-chip NFT collections use it.

Blockchains summarise a block's transactions in a hash tree named after whom?

The Merkle tree is named after Ralph Merkle, who patented the structure in 1979; it lets a light wallet prove a single payment is in a block without downloading the whole thing.

Ross Ulbricht ran his darknet market under which alias borrowed from The Princess Bride?

Ulbricht's alias Dread Pirate Roberts comes from The Princess Bride, where the name is handed from one pirate to the next; he served over 11 years before a January 2025 presidential pardon.

How many bitcoins were on the hard drive James Howells binned in a Newport landfill?

Howells' drive held about 8,000 bitcoin when it was binned in 2013; he offered Newport council a cut of the proceeds to dig, was refused over methane and asbestos risks, and lost a High Court claim in January 2025.

In which city did the world's first Bitcoin ATM open in October 2013?

The Robocoin machine opened in a Waves coffee shop in downtown Vancouver on 29 October 2013; Europe's first followed in Bratislava that December, and America's first lasted 30 days in an Albuquerque cigar bar.

Which Michael Saylor software firm began buying bitcoin as a treasury asset in 2020?

MicroStrategy, run by Michael Saylor, bought its first $250 million of bitcoin in August 2020 as a treasury asset and kept buying; it rebranded as Strategy in February 2025.

Bitcoin's mining difficulty is recalibrated after every how many blocks?

Difficulty adjusts every 2,016 blocks, which works out to roughly two weeks; the adjustment keeps blocks arriving about every ten minutes no matter how much hardware joins or leaves.

How many satoshis make one bitcoin?

One bitcoin is 100 million satoshis, the 'sat' being the smallest amount the protocol can record, so tiny payments need a second layer; a millibitcoin is a thousandth of a coin.

In which year did bitcoin first trade above $100,000?

Bitcoin first crossed $100,000 on 5 December 2024, weeks after Donald Trump won the presidency promising to make the US the 'crypto capital of the planet'.

Whose first-ever tweet sold as an NFT for $2.9M in March 2021?

Jack Dorsey's first tweet, 'just setting up my twttr' from March 2006, sold as an NFT for about $2.9 million to crypto entrepreneur Sina Estavi in March 2021, at the height of the NFT boom.

Which nation's bobsled team reached Sochi 2014 thanks to a Dogecoin community fundraiser?

Dogecoin users raised about $30,000 in January 2014 to send Jamaica's two-man bobsled team to Sochi; the same community then sponsored NASCAR driver Josh Wise and dug a well in Kenya.

The 2020 hijack of 130 high-profile Twitter accounts pushed what kind of scam?

The July 2020 hijack pushed a bitcoin giveaway scam: accounts including Elon Musk's and Joe Biden's promised to double any coins sent to an address, netting about $120,000; a Florida teenager was charged within weeks.