Bitcoin (BTC-USD), Ripple (XRP-USD), and most other leading cryptocurrencies are well in the red after the first month of 2018. Concerns about stronger regulatory action pressured the cryptocurrency markets throughout most of January. Only one of the top five cryptocurrencies — Ethereum (ETH-USD) — finished the month with a gain.

What were the forces behind January’s cryptocurrency price moves, and what financial measure should prospective cryptocurrency investors focus on?
Ethereum was the big winner of January
Unlike most of its peers, second-largest cryptocurrency Ethereum (ETH-USD) had a great January. Most of the gains took place toward the beginning of the month after reports that Ethereum network transaction volume had doubled and that there had been instances of more than 10 transactions being processed per second.

One important takeaway
If you’re not a cryptocurrency investor yet and are thinking about buying one of these (or any other) digital currencies, it’s important to recognize how volatile they can be. Pay particular attention to the “monthly change” column in the table above: The least volatile of the top five digital currencies moved by about 25% for the month, and January was actually a relatively quiet month by cryptocurrency standards.

An investment in cryptocurrencies can easily fluctuate by 25%, 50%, or even more in a relatively short period of time, so while there’s nothing wrong with speculating with your extra money, don’t put any money into cryptocurrencies that you aren’t willing and able to lose if things don’t go your way.