What Is Bitcoin?
Bitcoin is the first and best-known cryptocurrency, a digital money system described in a 2008 white paper by a pseudonymous author or group using the name Satoshi Nakamoto. The network began operating in January 2009. Bitcoin is not issued or controlled by any bank or government. Instead, users send value directly to one another, and the network keeps track of who owns what.
How It Works
Each transaction is broadcast to a global network of computers, called nodes, which check that the sender actually holds the coins being spent. Verified transactions are grouped into blocks and added to a shared record known as the blockchain. Because many participants hold copies of this ledger, altering past records would require controlling most of the network's computing power.
New bitcoin is created through a process called mining. Miners compete to solve computationally demanding puzzles using proof-of-work, and the winner adds the next block and receives newly issued bitcoin along with transaction fees. The protocol limits total supply to 21 million coins. The reward for mining new blocks is cut in half roughly every four years in an event known as the halving.
Ownership is controlled through cryptographic keys. A private key authorizes transfers, and anyone who loses it generally loses access to the coins it controls. Users typically store keys in software or hardware digital wallets.
Why It Matters to Investors
Bitcoin's price is set by trading on exchanges and can move sharply over short periods. Supporters point to its fixed supply and independence from central banks. Critics raise concerns about price swings, security risks at exchanges, the energy used in mining, and its use in illicit activity. Its price swings are a major reason it is often discussed in terms of volatility.
Regulation of crypto assets differs by country and continues to evolve, which can affect how Bitcoin is held, traded, and taxed. This entry is educational only and does not suggest whether Bitcoin is a suitable investment for any person.
Updated October 21, 2026. For general education only; not financial, tax or legal advice.