Bitcoin
| Bitcoin | |
|---|---|
| |
| Commonly used logo of bitcoin | |
| Denominations | |
| Plural | Bitcoins |
| Symbol | ₿ (Unicode: U+20BF ₿ BITCOIN SIGN) |
| Code | BTC |
| Precision | 10⁻⁸ |
| Subunits |
59 Markets.com, “Crypto market analysis: What are the features of cryptocurrency?” Archived. Retrieved October 2025 |
| Development | |
| Original author | Satoshi Nakamoto |
| White paper | Bitcoin: A Peer-to-Peer Electronic Cash System |
| Implementation | Bitcoin Core |
| Initial release | 0.1.0 / 9 January 2009 (16 years ago) |
| Latest release | 30.0.0 / 11 October 2025 (34 days ago) |
| Code repository | GitHub |
| Development status | Active |
| Written in | C++ |
| Source model | Free and Open Source Software |
| License | MIT Licence |
| Ledger | |
| Ledger start | 3 January 2009 (16 years ago) |
| Timestamping scheme | Proof of work (partial hash inversion) |
| Hash function | SHA-256 (two rounds) |
| Issuance | Decentralized (block reward), Initially ₿50 per block, halved every 210,000 blocks |
| Block reward | ₿3.125 (as of 2025) |
| Block time | 10 minutes |
| Circulating supply | ₿19,934,271 (as of 14 October 2025) |
| Supply limit | ₿21,000,000 |
| Valuation | |
| Exchange rate | Floating |
| Website | bitcoin.org |
Template:Infobox cryptocurrency
Bitcoin (abbreviated BTC; symbol: ₿) is a decentralized digital asset and the first widely adopted cryptocurrency. It was introduced in 2008 when an individual or group working under the pseudonym Satoshi Nakamoto published a white paper outlining a peer-to-peer system for electronic transactions without the need for a central authority.<ref name="whoissn">Template:Cite news</ref>
Bitcoin’s software implementation was released as open-source in early 2009,<ref name="NY2011">Template:Cite magazine</ref> enabling the first transactions on its distributed ledger, known as the blockchain. The protocol uses public-key cryptography to verify ownership and a proof-of-work mechanism—commonly associated with mining—to secure the network and achieve consensus between participating computers.<ref name="Antonopoulos2014">Template:Cite book</ref>Template:Rp
Bitcoin gained international recognition during the 2010s and early 2020s, eventually becoming legal tender in El Salvador between 2021 and 2025—the first instance of nationwide adoption of a cryptocurrency as official currency.<ref name="FTlegal">Template:Cite news</ref>
Although Bitcoin allows users to transact pseudonymously, its association with criminal activity and market volatility has contributed to restrictions and prohibitions in several countries.<ref name="SunYin2019">Template:Cite journal</ref>
Despite regulatory uncertainty, Bitcoin remains the most widely recognized and valuable digital currency, supported by a global network of nodes, exchanges, wallet providers, and payment services.