$BTC **$BTC (Bitcoin)** is the first and most valuable cryptocurrency, created in 2009 by Satoshi Nakamoto. As decentralized digital money, it operates on blockchain technology without banks or governments. Bitcoin's fixed supply of 21 million coins makes it deflationary, often called "digital gold." Its price is highly volatile but has seen massive long-term growth, attracting investors and institutions. Major companies like Tesla and MicroStrategy hold BTC as a treasury asset. While criticized for energy use, Bitcoin mining increasingly adopts renewable energy. Today, BTC is a global asset class, used for payments, trading, and hedging against inflation.