黄金将成为下一个泡沫吗?

It's been the amazing, runaway boom of the past decade. If you'd put your money into gold at the lows about 10 years ago, you'd have made a nearly 400% return. That's left pretty much everything else-stocks, China, let alone housing-in the dust.

But with gold now trading near record highs, the big $1,200-an-ounce question is obvious.

Is the gold rush over?

Some smart people wonder. 'The time to buy gold was in 1999, not 2010,' Harvard professor Niall Ferguson tells The Wall Street Journal-though he added that momentum might still drive it higher. Others will tell you that 'the smart money got out of gold months ago.' But then people have been saying that for years.

They could be right, of course: The future by definition is unknowable.

But if gold is a bubble, here's why it may not be over-and, indeed, may it may be about to go vertical.

First, the recent rise is deceptive. Yes, gold has risen from around $250 an ounce to $1,200. But that rise started at very depressed levels. Gold had been falling in price for two decades. In 2000-01, it was at the bottom of a very deep bear market. It had touched historic lows compared to consumer prices or other assets like shares. A lot of the past decade's boom has simply seen it recover toward longer-term averages.

Second, before we assume the gold bubble has hit its peak, let's see how it compares with the last two bubbles-the tech mania of the 1990s and the housing bubble that peaked in 2005-06.

The chart is below, and it's both an eye-opener and a spine-tingler.

It compares the rise in gold today with the rise of the Nasdaq in the 1990s and the Dow Jones index of home-building stocks in the 10 years leading up to 2005-06.

They look uncannily similar to me.

So far gold has followed the same path as the previous two bubbles. And if it continues along the same trajectory-a big if-gold today is only where the Nasdaq was in 1998 and housing in 2003.

In other words, just before those markets went into orbit.

Maybe the smart money is out of gold today. But how easily we forget that the smart money got out of these past bubbles way too early. The really smart money knows you make the most money in a bubble right at the end, when it goes manic.

There are other reasons to think that gold is still a long way from that point.

Like the futures market. It is predicting gold will rise by just a few percent a year over the next few years. That's less than you'd get from municipal bonds.

When the market thinks an investment is going to underperform munis, it's safe to say we are not in the midst of euphoria.

And take a look at the coverage of this industry. At the peak of a bubble, the Wall Street analysts covering a sector are usually all bullish. This time around? Far from it. Of the analysts covering gold-mining giant Barrick Gold, only about two-thirds are publicly bullish, according to Thomson Reuters. By Wall Street standards, that's very restrained. Among those covering Newmont Mining and Randgold Resources, it's about half.

And on an anecdotal level, this doesn't feel like the peak of a bubble. Taxi drivers and bartenders may be talking about gold. But they aren't yet handing out mining tips.

There is, of course, no guarantee gold will turn into another mania. But the fact that we now seem to live in Bubblonia-the land of perpetual bubbles-would suggest there is a current opening for the role. And in many ways, gold may be well cast.

It has a 'This time is different' story line: The world's central banks are flooding the market with liquidity. That should inevitably devalue the currencies. Gold is the only 'currency' they can't just print.

It has an army of true believers behind it, ready to claim each rise as a 'victory' and to mock skeptics with the words 'They just don't get it.'

And it's easy to untether from reality. You can't value gold by traditional financial measures, as it generates no cash flow. So there's plenty of potential to value it by other means. Eyeballs, anyone?

Dylan Grice, a strategist at SG Securities in London, thinks global conditions today could unleash another gold boom like the one in the 1970s. Then, as now, the world lost confidence in the U.S. dollar as a store of value. Back then, central banks started hoarding gold instead. Today, he notes, they are net purchasers of gold for the first time since 1988.

And although gold has risen a long way, so has the U.S. money supply. Mr. Grice calculates that even at today's prices, the bullion that the U.S. government holds in places like Fort Knox is still only worth enough to back 15% of the U.S. monetary base. That is near a record low.

At the peak of the gold mania in 1979-80, gold prices rose so far that the backing exceeded 100%. How far would gold rise if that happened again? To around $6,300 an ounce, Mr. Grice says.

Once again: I am not saying gold is going into the stratosphere. I am saying there is a good case for saying it might.

Gold is a high-risk and potentially dangerous speculation. Anyone thinking of investing needs to do some serious thinking first.