I've gone back and forth on buying cryptocurrency for months now. At this point, I don't own any, but I'm considering investing a little money in digital coins. And if I do decide to go that route, Bitcoin (CRYPTO:BTC) is a likely candidate, mostly because I know more about it than other digital currencies.

But while I may put some money into Bitcoin in the near term, I won't be investing in it for retirement purposes. Here's why.

Bitcoin symbol on circuit board with graph

Image source: Getty Images.

1. It hasn't been around long enough

Bitcoin has been around for a little over a decade. But frankly, when I compare that time frame to the amount of time some of the stocks I hold have been around, it's a drop in the bucket.

A lot of the stocks I have in my portfolio have been around for many decades. Some have been around for more than a century. And that alone buys me some comfort that in the long run, these stocks are likely to perform well.

That doesn't mean none of my stocks will lose value or have a bad year. But the fact that the companies I invest in have been around a long time makes me feel good about incorporating them into my retirement savings strategy.

2. It's too volatile

Stocks are hardly a risk-free investment. In fact, near-retirees are often advised to start shifting away from stocks and loading up on bonds -- which are far less vulnerable to price fluctuation -- at the end of their careers to avoid taking on undue risk in their portfolios.

That said, I still believe that it's a good idea for retirees to have about half of their assets in stocks, at least at the start of retirement. But I feel differently about Bitcoin because it's proven to be far more volatile.

3. I'm not convinced it has staying power

If Bitcoin doesn't become a widely accepted form of payment, its value could easily plunge to the point where it's worth nothing. Right now, it's impossible to know whether Bitcoin will one day become as commonplace as an established currency like the U.S. dollar. But it's not a risk I'm willing to take for my retirement.

I'm well aware that Social Security will not pay me enough money to secure the retirement I want. And for that reason, I make a point to not only sock away money in a retirement plan, but also load up on stocks in my brokerage account with the goal of holding them all the way into my senior years.

I may decide to buy Bitcoin one of these days as a short-term investment and see how it goes. But I'm not counting on Bitcoin or any other cryptocurrency, for that matter, to fund my retirement.

In fact, any money I put into Bitcoin is money I have to tell myself I'm OK with losing, should it come to that. If I were to take that approach with my retirement savings, I'd be setting myself up for disaster.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.