Not long ago, Stephen Bachmann, a private-equity investor turned online wine store owner, posted a chart on his widely read blog about wine collecting. The dots on the graphic charted an investment starting at around $1,000 in 2003. They continued on a sustained northerly path — up 100 percent, up 200 percent — peaking above $4,000 in 2007.

If the average investor's E-Trade account looked like that chart, he would be popping open bottles of champagne. But the chart's subject did not concern the latest hot tech stock. It was not charting the performance of a 401(k) retirement fund. The liquid asset in question was literally liquid: a single bottle of 1990 Petrus, a Bordeaux blend.

"If you didn't know what that was, most people would look at that chart and say that looks like a pretty good investment," said Bachmann, the founder of Vinfolio, based in San Francisco.

Wine is so hot, with demand growing from new wealth centers in China and Russia, that the prices of even some second-tier wines are rising at rates that make the Dow Jones industrial average look as if it's measuring the performance of low-risk municipal bonds. The jump in prices is causing collectors to liquidate parts of their cellars. There are wine investment funds, and there is even an electronic trading exchange in London for fine wine. It's up 39 percent this year, trailing gains in oil by only seven points.

For many, all this sounds too much like the legendary — and popped — tech bubble that cost investors millions of dollars earlier this decade. For others, who don't see demand ebbing any time soon, wine has become a surprising, though highly risky, way to produce returns from an urbane hobby.

"When one sees an opportunity, one would be a fool to let it go," said California attorney Dan Bailey, who has emptied his cellar of his Bordeauxs. He sounds almost surprised at what he's doing: "I guess I invest, yes."

And it hasn't been exactly difficult. Last month, Bailey spotted 10 bottles of some rare Burgundy at a local wine store. He liked the price: about $3,500 for them all. The thought of drinking the wine never even crossed his mind. He said he sold them for $10,000 two weeks later. "The demand is just flat-out crazy," Bailey said.

How this all happened is primarily a story of supply and demand. Good wine is extremely limited: It's not as if most vintners can magically increase their output, and sometimes years can go by between super quality vintages. But the wine boom is also a lesson in how the Internet creates fluidity in a fractured market, connecting buyers, as Bailey put it, "way out there in the world on the demand curve."

Wine can now be bought and sold over the Internet, particularly at auction through well-known wine stores such as Acker Merrall & Condit in New York or through www.WineBid.com, one of several popular wine auction Web sites.

With demand so strong, even owners of below-first-tier wines can fetch big premiums for the stuff.

Jerome Zech, chief executive of WineBid.com, remembers buying a bottle of 1990 Pichon Lalande for $29.95 in 1994. Now that wine is selling on his Web site for $140. That's a 367 percent increase in value.

"Things are really different in the wine business than 10 years ago, when most of the auctions were closed and they were in New York or London," Zech said. "The Internet has allowed people to see pricing globally and to access wines they wouldn't have been able to. A closed, clubby environment has really opened up."

But that certainly doesn't mean that investors should dive right in. The risks and challenges of wine investment are many.

For starters, much of the value of wine is determined by the opinions of a handful of influential critics such as Robert Parker.

Bachmann, on his blog, wrote: "Should a major wine critic later downgrade his rating of a wine you own, you'll see the value of your wine fall. Conversely, upgrades raise the value. The only problem is that this volatility is completely out of your control."

Also, because wine investing is not regulated, novices can easily become victims of fraud.

And the start-up costs are high because of the difficulty of properly storing fine wine.