If you took a chance on bitcoin early on, just a few years ago, your investment could have paid off in a big way.

According to digital-currency website CoinDesk — whose Bitcoin Price Index tracks prices from digital currency exchanges Bitfinex, Bitstamp, Coinbase and itBit — the value of bitcoins was volatile in 2013, particularly toward the end of the year: In December alone, the price per bitcoin hit highs of around $1,000 and lows below $600.