"Paper" isn't a recognized cryptocurrency. If you meant to ask about a specific cryptocurrency, here are some popular options:

- *Bitcoin (BTC)*: The most widely recognized cryptocurrency, known for its store of value and medium of exchange properties.

- *Ethereum (ETH)*: A popular platform for decentralized applications (dApps) and smart contracts.

- *Other Options*: If you have a specific cryptocurrency in mind, please provide more details or context.

If you're interested in learning more about cryptocurrencies or exploring investment opportunities, I'd be happy to help. Some popular exchanges include Binance, Coinbase, and Kraken.