What is Bitcoin (BTC)?
Bitcoin (BTC) is the first decentralized cryptocurrency, a digital money whose ledger is verified by a global network without any central authority. Bitcoin went live in January 2009, launched by the pseudonymous Satoshi Nakamoto, and anyone can send or receive it without permission from a bank or government.
Bitcoin is often called 'digital gold' because its protocol caps total supply at 21 million coins, making it scarce. Bitcoin was first promoted as a payment method, but today it is more widely viewed as a store of value similar to gold.
What is Bitcoin's supply and what is the halving?
Bitcoin follows a halving rule that cuts the mining reward in half roughly every four years (210,000 blocks), and the most recent halving in April 2024 set the block reward at 3.125 BTC. Bitcoin's circulating supply passed 20 million coins on March 9, 2026 according to CoinDesk, and stood at about 20.06 million as of July 2026.
Bitcoin's remaining roughly one million coins will be mined ever more slowly as halvings continue, with the last bitcoin estimated to be mined in the early 2100s. Bitcoin's supply schedule is fixed in code and predictable, which is its sharpest contrast with fiat money managed by central banks.
Bitcoin market history shows bull runs following past halvings, but analysts increasingly argue that spot ETF flows now influence price more than the halving does.
24h Change-3.51%
7d Change-11.87%
Market Cap$1,341,869,400,420
24h Volume$32,064,762,986
24h High$69,507
24h Low$66,492
All-Time High$126,080
How does Bitcoin work?
Bitcoin transactions are grouped into a block roughly every 10 minutes on average and recorded on the blockchain. Bitcoin miners compete using large amounts of computing power to produce each block and earn newly issued bitcoin plus fees, a system known as proof of work (PoW).
Bitcoin transactions recorded on the blockchain are effectively irreversible, and no single institution can inflate supply or freeze an individual wallet. Bitcoin's censorship resistance is widely regarded as the core property of its decentralized network.
How have spot Bitcoin ETFs affected the market?
Spot Bitcoin ETFs were approved in the US in January 2024 and became a main channel for pension funds, corporations and asset managers to gain Bitcoin exposure. US spot Bitcoin ETFs had cumulative net inflows of about $57.6 billion and net assets of about $108.4 billion as of September 26, 2026, according to The Block.
Bitcoin ETF flows swung sharply in 2026: year-to-date net outflows reached about $5.7 billion on July 13, 2026, before turning back to net inflows on September 22, per The Block. Bitcoin ETFs are also being accepted by some banks as loan collateral, a sign of deeper integration with traditional finance.
Bitcoin hit an all-time high of about $126,000 on October 6, 2025 per CoinGecko data, and traded roughly between $76,000 and $87,000 in September 2026 per CoinGecko. Bitcoin therefore remains a highly volatile asset even after institutional adoption.
How is Bitcoin evolving?
Bitcoin, unlike Ethereum, has no roadmap of frequent major upgrades and treats resistance to rule changes as a strength. Bitcoin's surrounding ecosystem keeps growing instead, including the Lightning Network (a Layer 2) for instant small payments and Ordinals and Runes for inscribing data and tokens on Bitcoin.
Bitcoin's community is debating open questions such as whether the four-year cycle still applies in the ETF era and how to migrate to quantum-resistant signatures over the long term. Bitcoin adoption as a sovereign or corporate reserve asset and the growth of derivatives such as ETF options are also closely watched.
What are the risks of Bitcoin?
Bitcoin is highly volatile; per CoinGecko data, its price in early September 2026 was roughly 40% below the October 2025 all-time high. Bitcoin prices are sensitive to macro factors such as interest rates and a strong dollar, as well as to regulatory changes.
Bitcoin can fall more steeply when large amounts leave ETFs, and critics point to mining's energy use and to quantum computing as a distant potential threat. This Bitcoin article is for information only and is not investment advice; investment decisions are your own responsibility.
