Bitcoin (abbreviation: BTC; sign: ₿) is the first decentralized cryptocurrency. Based on a free-market ideology, bitcoin was invented in 2008 when an unknown person published a white paper under the pseudonym of Satoshi Nakamoto.[4] Use of bitcoin as a currency began in 2009,[5] with the release of its open-source implementation.[6]: ch. 1 From 2021 to 2025, El Salvador adopted it as legal tender currency before revoking it.[7][8][9] As bitcoin is pseudonymous, its use by criminals has attracted the attention of regulators, leading to its ban by several countries.[10]
Bitcoin
Prevailing bitcoin logo
Commonly used logo of bitcoin
Denominations
Plural
bitcoins
Symbol
₿
(Unicode: U+20BF ₿ BITCOIN SIGN)[1]
Code
BTC
Precision
10−8
Subunits
1⁄1000
millibitcoin
1⁄1000000
microbitcoin
1⁄100000000
satoshi[a][2]
Development
Original author
Satoshi Nakamoto
White paper
"Bitcoin: A Peer-to-Peer Electronic Cash System"
Implementation
Bitcoin CoreBitcoin (abbreviation: BTC; sign: ₿) is the first decentralized cryptocurrency. Based on a free-market ideology, bitcoin was invented in 2008 when an unknown person published a white paper under the pseudonym of Satoshi Nakamoto.[4] Use of bitcoin as a currency began in 2009,[5] with the release of its open-source implementation.[6]: ch. 1 From 2021 to 2025, El Salvador adopted it as legal tender currency before revoking it.[7][8][9] As bitcoin is pseudonymous, its use by criminals has attracted the attention of regulators, leading to its ban by several countries.[10]
Bitcoin
Commonly used logo of bitcoin
DenominationsPluralbitcoinsSymbol₿
(Unicode: U+20BF ₿ BITCOIN SIGN)[1]CodeBTCPrecision10−8Subunits 1⁄1000millibitcoin 1⁄1000000microbitcoin 1⁄100000000satoshi[a][2]DevelopmentOriginal authorSatoshi NakamotoWhite paper"Bitcoin: A Peer-to-Peer Electronic Cash System"ImplementationBitcoin CoreInitial release0.1.0 /
Initial release
0.1.0 /