With cryptocurrencies so much in the news, you might be wondering if you should invest in them. But “invest” may not be the right word – because, in many ways, cryptocurrencies, or “crypto” for short, are more speculation than investment.

But what’s really the difference between a speculator and an investor? Probably the main factor is the differing views of time. A true investor is in it for the long term, building a portfolio that, over many years, can eventually provide the financial resources to achieve important goals, such as a comfortable retirement. But speculators want...