If you’ve been thinking about pulling out your gold fillings, or melting down the gold wedding ring your ex-wife threw in your face, you’d better get on with it. The way gold is trading on the financial markets, it won’t be worth your while unless you act soon. In the past two days, the spot price of the precious metal has fallen by almost a hundred dollars, to one thousand three hundred and seventy-five dollars an ounce. It’s the biggest two-day fall in thirty years. Since November, the price is down about four hundred dollars—or about twenty per cent.

Why’s this happening? The proximate answer is because traders are selling. Beyond that, nobody knows for sure. Trying to explain what’s happening in a speculative market like gold is a bit like trying to say why lightning strikes one place but not another. We know the general principles involved, but beyond that it’s mostly guesswork. Still, here are six theories, which I’ve ordered by increasing plausibility.

1. The bitcoin factor

Beyond its industrial and cosmetic uses, gold performs two functions in the economic system. It’s a store of value, and it’s an object of speculation. In recent years, speculation has been rampant, with hedge funds, mutual funds, exchange-traded funds (E.T.F.s), and individual investors bidding the price up from six hundred dollars an ounce in 2007 to a peak of $1,920.30 in September, 2011. Recently, though, bitcoin, the virtual currency, has been stealing some of gold’s speculative lustre, with everybody from Maltese hedge funds to the Winklevoss brothers piling in. Could this be responsible for gold’s tumble?

No. The gold market is huge. Every day, tens of millions of ounces are traded on commodity exchanges in London, New York, and Tokyo, and that might be an underestimate. Some traders say the market is worth five trillion dollars a year. By comparison, the bitcoin market is tiny. At its peak, it was worth about three billion dollars, which, in the markets, is next to nothing. Moreover, the timing doesn’t work. If speculators were selling gold to buy bitcoins, the virtual currency should be going up. But last week it fell even further than gold, handing big losses to the Winklevii and other speculators.

2. The Goldman conspiracy theory

After writing about the markets for more than twenty-five years, I’ve come up with an informal rule: where there’s trouble, there you will find Goldman. This isn’t a criticism or an indictment; it’s merely an empirical observation. The bank is so big and so aggressive that it gets involved in virtually everything, so when the C.S.I. squads turn up to examine the body, they usually find some Goldman D.N.A.

The gold bust is no exception. Last December, Goldman’s economic team turned bearish on gold, saying the multi-year upward trend in gold prices “will likely turn in 2013.” And last Wednesday, the bank’s commodities team advised its clients to start shorting gold, saying, “While we may be end up [sic] too early in entering this trade, we prefer that to being late given our belief that the skew to current prices is to the downside.” The timeline is suggestive, but this looks more like a case of Goldman having good foresight rather than anything more sinister. There’s no evidence the firm itself had a huge short on, and its analysts weren’t the only ones warning that gold’s big run might be coming to an end. On April 2nd, Société Générale, the French bank, issued a report entitled “The End of the Gold Era” that said the recovery of the U.S. economy and the rise in the dollar could create a “perfect storm” in the gold market.

3. It’s just a correction

One of the great mysteries of the financial markets is this: when everyone’s selling, who’s doing the buying? Sometimes, it is contrarian speculators who believe the sell-off has gone too far. Thus, in the past couple of days, while many investors in gold have been panicking, some folks have been taking advantage of what they view as a buying opportunity. At Business Insider this morning, there was a useful roundup of what these gold bugs have been saying. Some of it is plain crazy—talk about a Fed conspiracy and the like. But there is an argument that the price drop has been accentuated by forced selling on the part of leveraged funds and investors, who are facing margin calls. The question is what will happen when this panic selling stops. Will the price of gold start rising again? To answer that question in the affirmative, you have to believe one of the fundamental stories about why gold is so attractive.

4. Chinese economic weakness

Many of today’s news stories about the gold price emphasized disappointing economic figures from China, which showed economic growth slowing down slightly in the first three months of 2013. China is a big consumer of virtually all natural resources, and gold was but one of many commodities that fell sharply after the report from Beijing. The prices of oil, copper, and many other metals also slumped.

Still, there are at least two problems with this theory. First, the purported slowdown in the Chinese economy was very slight. First quarter growth came in at 7.7 per cent, compared to 7.9 per cent in the last three months of 2012. Allowing for the vagaries of the statistics, the difference is inconsequential. Second, the gold price started plummeting last Thursday and Friday, before the news from China. The disappointing figures added to the sell-off; they didn’t initiate it.

5. The inflation phantom has been slain

The bullish argument for gold is deceptively simple. With central banks the world over printing money hand over fist to revive their economies, inflation will eventually rise sharply, destroying the value of many assets, such as cash held in bank accounts and (non-index-linked) bonds. Gold, as a widely accepted inflation hedge, will be one of the few assets that retains its value. But these predictions have not been borne out. After more than four years of quantitative easing in the United States, the inflation rate, as measured by the consumer price index, is running at just two per cent. According to other measures, such as the G.D.P. deflator, the inflation rate is even lower. In Britain, where the Bank of England has followed policies similar to the Fed’s, the inflation rate is 2.8 per cent—a bit higher, but hardly alarming.

And now comes news that Ben Bernanke and his colleagues on the Fed’s policy-making committee are talking about bringing quantitative easing to an end earlier than expected—possibly as soon as later this year. The news of this development, which was contained in the minutes of the committee’s last meeting, came out early last week, just before the gold price started to crater. If the argument that the Fed is intent on debauching the currency is removed from their armory, the gold bugs won’t have much to say, beyond evoking memories of wheelbarrows and Weimar Germany.

6. The great panic of 2008-09 is finally over

Ultimately, the price of gold is a fear index. When it looks like the economy is going to hell, as it did from 2007 to 2009 in the United States, and as it has in Europe since 2009, speculators pile into gold in the belief that others will view it as a store of value. Since others believe the same thing, the process is self-reinforcing: a bull market starts, and some of the first movers make a mint. During the OPEC crisis of the late seventies, the same thing happened. Between 1977 and 1980, the price of gold rose to a level that is still an all-time high after accounting for inflation. But when the thing that is making people nervous goes away, the reason for buying gold goes with it, and the price plummets. After the crisis, until 2000, oil prices fell and remained low. OPEC’s grip on the market was greatly diminished, and the price of gold fell by more than seventy-five per cent, after adjusting for inflation.

Is something similar happening now? It could well be. Come September, it will have been five years since the collapse of Lehman Brothers. The markets are hitting new highs, and the banks—even Citigroup—are making money again. Talk of a financial meltdown seems old. Elsewhere, Europe appears to have weathered the crisis in Cyprus, much of the developing world is powering ahead, and even moribund Japan is taking action to revive its economy. With the sense that the global economy is in crisis having receded, it was always just a matter of time before the change in sentiment would be felt in the gold market. Now that time has come.

This doesn’t mean the gold price will never go back up. Lots of bad things could still happen to the world. If economic growth in the United States or China fell sharply, prompting expectations of yet more monetary easing; if Abenomics led to a collapse in the value of the yen; or if Spain or Italy were forced into emergency bailouts, the gold bugs would be back in force. For now, though, it looks like they’ve had their day.

Illustration by Jeroen Koolhaas.