$BTC Here are some popular coin pairs for Bitcoin (BTC):

*Popular BTC Pairs*

1. *BTC/USDT*: Bitcoin paired with Tether USD

2. *BTC/USD*: Bitcoin paired with US Dollar

3. *BTC/EUR*: Bitcoin paired with Euro

4. *BTC/JPY*: Bitcoin paired with Japanese Yen

5. *BTC/GBP*: Bitcoin paired with British Pound

6. *BTC/AUD*: Bitcoin paired with Australian Dollar

7. *BTC/CAD*: Bitcoin paired with Canadian Dollar

*Crypto-Crypto Pairs*

1. *BTC/ETH*: Bitcoin paired with Ethereum

2. *BTC/LTC*: Bitcoin paired with Litecoin

3. *BTC/BCH*: Bitcoin paired with Bitcoin Cash

4. *BTC/XRP*: Bitcoin paired with Ripple

5. *BTC/DOGE*: Bitcoin paired with Dogecoin

Note that this is not an exhaustive list, and there may be other BTC pairs available on various cryptocurrency exchanges.