$BTC A coin pair like BTC/USD represents the exchange rate between Bitcoin and the US Dollar. In trading, the first currency (BTC) is the base, and the second (USD) is the quote. The price shows how much of the quote currency is needed to buy one unit of the base. Traders use coin pairs to speculate on price movements, buy or sell assets, and determine market strength. Pairs can be crypto-to-fiat (BTC/USD) or crypto-to-crypto (BTC/ETH). Liquidity, volatility, and trading volume vary across pairs. Understanding coin pairs is essential for executing effective trades and interpreting market data in real time.