Cryptocurrencies utilize blockchain technology to record and verify transactions on a distributed ledger. It can be thought of as a shared public distributed database.
Blockchain is reportedly difficult to hack since it is decentralized. However, hackers have successfully stolen cryptocurrencies from wallets and exchanges.
Volatility is the price fluctuation of a tradeable asset. Cryptocurrencies, like Bitcoin, are volatile. For instance, Bitcoin’s price has fluctuated between a low of ~$29,800 to a high of about ~$67,600.
There are 19.1 million Bitcoins in circulation, and thus the total market capitalization is more than $780 billion. The limit on the number of Bitcoins is 21 million.
Ethereum is the second most common cryptocurrency to invest in, with about 19.5% market share. Although Ethereum is a cryptocurrency, it is not the same as Bitcoin and targets a different market niche.