$BTC When trading cryptocurrencies, you will often encounter the pair $BTC. This abbreviation usually refers to Bitcoin (BTC) in a pair with another currency or asset, such as BTC/USD, BTC/EUR, or BTC/USDT. The first coin in the pair is what you are buying or selling, and the second is the currency you are doing it for. Understanding what exactly $BTC is traded against is extremely important for market analysis and making informed decisions.