Gold has had a great run over the past decade. It’s been the amazing, runaway boom and if you had put money into gold at the lows about 10 years ago, you’d have made a nearly 400% return. That is a better performing investment than anything else—stocks, China, housing…..

With gold now trading near record highs, the big question is can gold sustain a price of $1,200 an ounce. Is the gold rush over?

Many people wonder. Was the time to buy gold was in 1999, not 2010? Momentum might still drive gold prices higher and others will tell you that the smart money got out of gold months ago. They could be right, of course future unknowable, but if gold is a bubble, there is evidence that it may not be over—and, indeed, may it may be about to go higher.

The recent rise is deceptive, the price of gold has risen from around $250 an ounce to $1,200. 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 after the big Y2K. It had nearly reached historic lows compared to consumer prices or other assets like shares. A lot of the past decade’s boom has simply seen it recover towards longer term price averages.

Before we assume the gold bubble has hit its peak, let’s look back at how it compared with the last two bubbles; the tech mania of the 1990s, and the housing bubble that peaked in 2005-06. So far gold has followed the same path as the previous two bubbles, and if it continues along the same trajectory, gold today is only where the Nasdaq was in 1998 and housing in 2003. In other words, just before those markets went manic.

Smart money may be 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. this however is a risky and calculated move.

There are other reasons to think that gold is still a long way from that manic point. 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 on the bubble. Also 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. However they are far from being bullish right now. 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.

Of course there no guarantee gold will turn into another mania, but the fact that we now seem to live in a age of perpetual bubbles would suggest there is room for one more. This time is different? The world’s central banks are flooding the market with liquidity. That should inevitably devalue the currencies. Gold is the only currency that just can’t be printed and it has many followers and believers, ready to claim each rise as a "victory" and to mock skeptics.

It’s easy to disconnected from reality, because 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. 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? Mr. Grice says, to around $6,300 per ounce of gold.