Everyone is talking about bitcoin, even people who otherwise know little about investing. That’s probably a bad sign for bitcoin.

Recently, I had a conversation with my 89-year-old father. He likes reading newspapers, so this year I got him a Wall Street Journal subscription. Now he’s up on the financial news.

A few weeks ago, he asked the big question: “What is bitcoin?”

I told him what I knew: Bitcoin is a digital currency, designed to be scarce, anonymous, and secure, that it’s price has gone vertical, that some people think it will one day replace dollars.

He was with me until that last part. A private, digital-only currency didn’t make sense to him.

I pondered that conversation driving home… and I think he was right. Bitcoin may be useful and valuable, but it won’t replace fiat currencies anytime soon.

Photo: Getty Images

Power Mining

Unless you’ve been hiding under a rock, you know bitcoin prices have gone bananas. I’m not even going to quote any numbers. Anything I say will be laughably wrong by the time you read this.

Could some virtual currency that only exists on a computer screen really be worth these crazy prices?

Maybe. If you think it will become a major medium of exchange, bitcoin is far underpriced.

That’s a big “if” we’ll discuss in a minute. First, let’s look at some more practical issues.

Bitcoins enter the digital world when someone “mines” them by solving certain math problems. Mining operations have turned from college students sitting at their laptops to huge enterprises that use massive computing power to run ever more complex math calculations. Some of the computers dedicated to solving those math problems fill entire buildings.

Photo: Getty Images

Bitcoin’s anonymous inventor, who called himself Satoshi Nakamoto, built scarcity into the system. Mining gets more difficult as time passes and the supply increases. No one will ever hit a mother lode and double the bitcoin supply overnight.