Bitcoin has been in the news a lot recently. Today, you can buy a bitcoin for just 16,000 USD. Tomorrow, however, there is no telling how much they could be worth. The price fluctuation of the bitcoin makes it a risky investment.
With risk comes great reward though. According to Coindesk, there was a point in 2011 that you could have bought a bitcoin for 3 dollars. Just last year you could have bought one for 800 dollars. If I spent nine dollars on bitcoin at that time in 2011, I would have almost $50k worth of bitcoin right now. With such a high reward, many people are more than willing to take the risk and invest in bitcoin.
The CEO of Coinbase urges people to invest wisely when it comes to bitcoin. The huge-and very random- fluctuation of the market value means that at any moment an investor can lose all of his or her money.
http://money.cnn.com/2017/12/09/investing/bitcoin-coinbase-warning/index.html