BITCOIN: THE ORIGINAL
Plain English
Bitcoin (BTC) is the first cryptocurrency — created in 2009. It's often called digital gold because of its fixed supply of 21 million coins and its store-of-value properties. It's the largest and most liquid crypto by market cap.
Going deeper
Bitcoin was introduced in a 2008 whitepaper by Satoshi Nakamoto titled 'Bitcoin: A Peer-to-Peer Electronic Cash System.' It uses a Proof of Work consensus mechanism where miners solve computational puzzles to validate transactions and earn newly created BTC. Bitcoin undergoes a 'halving' event approximately every 4 years, cutting the block reward in half — historically a major price catalyst. The 21 million supply cap is enforced by code. Bitcoin transactions are pseudonymous (not anonymous) and traceable on the public ledger. As the largest crypto by market cap (often 40-50%+ of total crypto market), Bitcoin's price movements heavily influence the entire crypto market.
Examples
The Halving Effect
In 2020, Bitcoin's block reward halved from 12.5 to 6.25 BTC. In the 12 months following, BTC price went from ~$9,000 to ~$60,000. Historically, halvings reduce new supply entering the market, creating upward price pressure if demand holds steady.
Bitcoin Dominance
When Bitcoin dominance (BTC's share of total crypto market cap) rises from 40% to 55%, it often means money is flowing from altcoins into BTC — a 'risk-off' signal in crypto. Traders watch this metric to time altcoin exposure.