Bitcoin is the first cryptocurrency, launched in January 2009 by the pseudonymous Satoshi Nakamoto. It runs on a proof-of-work blockchain secured by miners, with a hard cap of 21 million coins and a supply issuance that halves roughly every four years.
Launched
January 2009
Created by
Satoshi Nakamoto
Consensus
Proof of Work (SHA-256)
Supply
21,000,000 BTC
Bitcoin key facts
Fixed maximum supply of 21 million BTC, with issuance halving approximately every 210,000 blocks (about four years).
Secured by proof-of-work mining using the SHA-256 hashing algorithm.
Average block time of roughly ten minutes, adjusted by a difficulty retarget every 2,016 blocks.
Spot Bitcoin ETFs were approved in the United States in January 2024, opening institutional access through regulated brokerage accounts.
How Bitcoin works
Transactions are grouped into blocks and appended to a public ledger. Miners compete to find a hash below a target difficulty; the winner adds the next block and receives newly issued bitcoin plus transaction fees. Because rewriting history would require redoing that work, the chain becomes harder to alter as it grows.
What BTC is used for
A settlement network that does not depend on a bank or clearing house
A treasury reserve asset for companies and, increasingly, funds
Cross-border value transfer where local banking is slow or restricted
<p><strong>More than 6 million bitcoin — 31.2% of the entire circulating supply — now sit behind exposed public keys visible directly on the blockchain</strong>, according to new data from on-chain analytics firm Glassnode. The finding lands just a day after Ethereum researcher Justin Drake urged the crypto industry to prepare for "bunker mode," warning that artificial intelligence could crack wallet cryptography far sooner than most expect.</p><h2>What the New Glassnode Data Shows</h2><p>Glassn
Bitcoin's key moving averages are converging into their first fully bullish setup since June 2025, reinforcing a three-month recovery that has carried the token more than 40% higher even as this week's rally stalled just below $87,000.
Bitcoin is on pace for a rare positive September following a 25% August gain, a combination that would break a pattern holding since 2013, even as Treasury yields climb to multi-year highs.
Bitcoin ETFs have erased a $5.8 billion deficit and turned positive for 2026, with nearly $800 million in net inflows after six straight days of buying.
A House committee voted 28-21 to advance the American Reserve Modernization Act, which would codify Trump's Strategic Bitcoin Reserve and lock the coins under Treasury custody for 20 years.
Spot Ethereum ETFs attracted $196.9M in net inflows for the week ending September 11 — a fourth straight positive week — while Bitcoin ETFs bled $462.7M.
Price is set by supply and demand across global exchanges. Supply is fixed and predictable by protocol, so most short-term movement comes from demand — ETF flows, macro conditions such as interest rates, regulatory news, and large holders entering or exiting positions.
What is the Bitcoin halving?
Roughly every four years the reward paid to miners for each block is cut in half, which halves the rate of new supply entering circulation. It is written into the protocol and continues until the 21 million cap is reached, expected around the year 2140.
Is there a maximum number of bitcoin?
Yes — 21 million. No more can ever be created without changing the protocol rules, which would require agreement across the network. This fixed cap is the main reason Bitcoin is often compared to a commodity rather than a currency.
