Bitcoin (BTC) is a decentralized digital currency that operates on its own base-layer, UTXO-based Proof-of-Work blockchain, not a token issued on another chain.
Launched in January 2009, it enables peer-to-peer transfer of value without a bank or payment processor, with transactions recorded on a public, immutable ledger secured by a global network of miners rather than any central operator.
Bitcoin's core differentiator is a fixed, algorithmically enforced supply cap that no issuer can alter, combined with the deepest liquidity and largest market capitalization of any cryptocurrency.
As of 2026-08-31, market capitalization stood at roughly $1.58 trillion. Miners earned $938.21 million over a recent trailing 30-day period, with block subsidies rather than transaction fees supplying about 99.3% of that revenue, underscoring the network's continued reliance on issuance-driven security over fee demand.
Bitcoin is neither a governance token nor a utility token in the DeFi sense; it functions natively as a medium of exchange, store of value, and unit of account.
Holders transact BTC directly on the base layer, paying network fees denominated in BTC to miners. Miners in turn receive newly issued BTC plus fees as compensation for validating transactions and securing the network through Proof-of-Work; there is no staking, on-chain voting, or collateral-locking mechanism at the protocol level.
Bitcoin has a hard-capped maximum supply of 21,000,000 BTC, with approximately 20.08 million BTC in circulation as of 2026-08-31.
Bitcoin launched as free, open-source software with no ICO, private sale, or venture-capital funding round.
Satoshi Nakamoto published the whitepaper in October 2008, mined the Genesis Block on January 3, 2009, and released the client publicly on January 9, 2009. The only pre-issued coins are the Genesis Block's 50 BTC reward, which is cryptographically unspendable by protocol convention; every other BTC has entered circulation solely through public Proof-of-Work mining.
Bitcoin runs on its own base-layer blockchain, using an unspent-transaction-output (UTXO) model rather than an account-based ledger.
The network reaches consensus through Proof-of-Work: miners compete to solve a cryptographic puzzle, and the longest valid chain of blocks, each cryptographically linked to the one before it, represents the agreed-upon transaction history. There is no separate validator set or staking mechanism; mining is open and permissionless.
Bitcoin was created by a pseudonymous individual or group known as Satoshi Nakamoto, whose true identity has never been confirmed.
Nakamoto published the Bitcoin whitepaper in October 2008, mined the Genesis Block on January 3, 2009, and sent the first BTC transaction (10 BTC) to cypherpunk developer Hal Finney on January 12, 2009, before stopping public communication around 2010-2011.
Bitcoin has no issuing organization: it launched as open-source software with no company, foundation, or fund behind it, and no ongoing corporate issuer.
Development of the reference client, Bitcoin Core, is carried out today by a decentralized, volunteer open-source community rather than any single entity.
Bitcoin has no on-chain token voting and no formal governing body; protocol changes proceed through the public Bitcoin Improvement Proposal (BIP) process requiring broad miner and ecosystem consensus.
A BIP moves from Draft to Proposed to Final, and consensus-level changes need signaling thresholds among miners plus adoption by node operators, exchanges, and wallets. In August 2026, the contested BIP-110 anti-spam proposal required 55% miner signaling to activate but received only about 2.53%, so it failed and a minority fork it spawned stalled after two blocks.
Bitcoin's base layer has no centralized product roadmap; near-term developments center on contested Bitcoin Improvement Proposals and external regulatory milestones.
Recent months have featured active debate over proposals such as the BIP-110 anti-spam proposal, reflecting the deliberately conservative pace of base-layer change. Separately, the U.S. CLARITY Act faced a key Senate test around September 15, 2026, a regulatory development closely watched by the Bitcoin market.
Bitcoin has no smart-contract audit, since its base layer hosts no smart contracts; its security instead relies on Proof-of-Work's economic cost. With network hashrate around 1,000 EH/s, a theoretical 51% attack is estimated to cost several billion dollars in hardware alone.
Bitcoin Core follows a formal disclosure policy, delaying medium/high-severity bug details until affected versions reach end-of-life. Past vulnerabilities include the critical CVE-2018-17144 inflation bug, patched before exploitation, and CVE-2024-52911, reported by developer Cory Fields and fixed in Bitcoin Core 29.0.