$BTC

BTC (Bitcoin) is the most widely traded cryptocurrency, and it's paired with numerous other cryptocurrencies and fiat currencies. Here are some popular BTC coin pairs:

Cryptocurrency pairs:

1. BTC/ETH (Bitcoin/Ethereum)

2. BTC/LTC (Bitcoin/Litecoin)

3. BTC/XRP (Bitcoin/Ripple)

4. BTC/BCH (Bitcoin/Bitcoin Cash)

5. BTC/USDT (Bitcoin/Tether)

Fiat currency pairs:

1. BTC/USD (Bitcoin/United States Dollar)

2. BTC/EUR (Bitcoin/Euro)

3. BTC/JPY (Bitcoin/Japanese Yen)

4. BTC/GBP (Bitcoin/Pound Sterling)

5. BTC/AUD (Bitcoin/Australian Dollar)

These pairs are widely available on cryptocurrency exchanges, such as:

1. Binance

2. Coinbase

3. Kraken

4. Huobi

5. Bitfinex

Remember to always research and understand the market dynamics before trading any cryptocurrency pairs.