**Bitcoin (BTC)** is the world's first and largest **cryptocurrency**, created in 2008 by the pseudonymous Satoshi Nakamoto and launched in January 2009. It operates as a decentralized digital currency on a peer-to-peer network, using **blockchain** technology to record transactions securely without intermediaries like banks or governments.

Key features include a fixed supply cap of **21 million coins** (to combat inflation), halvings every ~4 years that reduce mining rewards (last in 2024), proof-of-work consensus for security, and pseudonymous transactions via public addresses and private keys. Bitcoin enables borderless, censorship-resistant transfers, often called "digital gold" for its store-of-value properties.

As of January 2026, Bitcoin trades around **$89,000–$91,000** USD (based on recent market data), with ongoing debates about its future trajectory—some predict new highs above $100k–$200k, others warn of potential corrections or volatility influenced by global liquidity, regulations, and adoption trends like ETFs and institutional investment.

It powers a vast ecosystem: wallets, exchanges (e.g., Gate.io), mining, Lightning Network for fast/low-cost payments, and growing use in remittances, hedging, and payments. Despite criticisms (energy use, volatility), Bitcoin remains the benchmark for crypto, with unmatched network security and market dominance.