I am able to place an Elvis fan a mile away.

Major hair, jewelry, wide collars, an open shirt... and self-confidence.

I know there has to be bashful fans of the King on the market, but apparently, they don't wear it on their sleeves. If you're an Elvis fan on the inside and the exterior, your sartorial design will reflect it.

Therefore it was with this particular bitcoin-bug.

He had cornered me in Bermuda this past year. He asked my view of the cryptocurrency... but before I'd had an opportunity to respond, he explained what it ought to be.

"It's the single biggest innovation in world history," he exclaimed. Apparently writing and the wheel were small potatoes. "If you're not into it, you're crazy." Jarringly, the accent was more Long Island than Tupelo, Mississippi.

"Perhaps," I replied. "But the real question is, into it for how much?"

Occasions are asking you that question right now...

Recently, I got a note from a reader complaining that I talked too much about the effect of politics on groceries.

Then the governor of Guam told his fellow Guamanians not to look directly at a nuclear fireball, if a person should appear courtesy of North Korea.

As it always does, the gold price spiked, hitting $1,294 an oz.

Gold has a tradition of doing this. Gold graphs look like an EKG instead of price movements. Up, then down... up, then down... by strangely regular quantities.

Overall, gold is up more than 12 percent this year... but if history is any guide, those gains will halve shortly.

Something else happened recently. Bitcoin broke the $4,000 barrier.

And unlike gold, everyone's favorite cryptocurrency keeps trending upward this season. Aside from some blips in June and July, bitcoin is up, up and away.

If you had bought bitcoin at the beginning of January, you would be taking a look at that a 300% gain.

What Can You Afford: The Tortoise or the Hare?

When you call someone "volatile," you mean he's unpredictable.

People can be unpredictable even if they appear stable. I have known plenty of guys who had a werewolf-level transformation once they got a few drinks in.

As soon as we call an asset volatile, but it just means that its price bounces around a good deal. It might even do that predictably, like the gold cost.

Even though gold price has seesawed just like a little boat in a choppy sea, its volatility is still extremely low.

By comparison, bitcoin is all over the area.

The bitcoin Elvis I met in Bermuda was getting on a bit in years. I can't help but wonder how his metabolism has managed the cryptocurrency's crazy swings this year.

Perhaps he was wealthy and it did not matter. But I guess he was just like most of us... playing his riches to make it go farther as he got older. In that case I imagine he's had a lot of chamomile tea this season.

Bitcoin and gold are both primarily shops of value. Yes, you are able to pay for stuff with bitcoin, but most of it's in electronic vaults, waiting for the price to go up.

It's possible to pay for things with gold too, and most of it's in vaults as well, waiting for... well, for prices to go down. Stock costs, for instance.

To me that is the difference between bitcoin and gold.

Bitcoin is a risky play, like industrial metals. Big jumps and big drops are a part of the territory. It is like the hare, starting and stopping constantly. Its value is dependent upon something else... at bitcoin's case, on sentiment.

Gold, on the other hand, is the tortoise of the investment world. It is so stable that its buying power now is about the same as it had been in Roman times, as well as farther back. Its long-term value is eerily detached from human affairs.

Ask yourself: Can you afford to ride the bitcoin roller coaster? Both emotionally and financially, I mean. Or would you have been tempted to fear sell sooner this year... only to gnash your teeth as it topped $4,000?

In case you have a lot of cash... more than you'll ever need, today and later on... go along with bitcoin Elvis. It's going be exhilarating, for sure.

But if you are like most of us, also you will need a stable bank accounts and a secure psychological life, stick with gold.

In the end, we understand what it is going to be worth in the long run: the same as it has been for thousands of years.