Virtual cash seems to be worth quite a bit of real money these days.

That's been the experience of CyberCash Inc., a Reston-based company that has so far enjoyed a lucrative seven business days of life as a public company on the Nasdaq Stock Market.

CyberCash is a technology company that believes it has devised a way for people to pay for goods and services over the Internet without sending their credit card information through the ether. It has yet to report any revenue.

The company offered its first 2.4 million shares of stock for $17 apiece when trading opened on Feb. 15. Yesterday, it closed at $56.75, down 25 cents from its high of $57 reached the day before.

Traders are swapping the stock energetically, moving more than 3 million shares yesterday -- and making the stock as actively traded as the likes of more established companies such as America Online Inc. and Tele-Communications Inc. CyberCash's price fluctuated wildly yesterday, rocketing to more than $64 and dropping to less than $48.

So what's pushing the stock? People believe that commerce on the Internet will be big business, say investors, and CyberCash is one of the few firms that is devoting itself exclusively to helping payments take place.

"Someone's got to win, and they're one of the best positioned to win," said Peter Barris, a general partner with New Enterprise Associates, a leading venture capital firm based in Baltimore.

Investors also take a close look at the management team, and CyberCash has assembled a seasoned crew, Barris said. For instance, William Melton, the company's chief executive, made his fortune by founding VeriFone, a company that builds the technology that automates credit credit transactions. CyberCash's chairman, Daniel Lynch, made his fortune founding Interop, a conference and trade-show company dealing with the computer industry.

"They've got an excellent management team who knows the {financial} payment side of the business and the technology," Barris said.

The company also got a boost last week when Softbank Corp., a large Japanese computer software distributor, said it would buy a 9.9 percent stake in it for about $15.2 million.

Still, as a company with a total of $11 million in losses since its founding 18 months ago, CyberCash has its risks. Traditional methods of measuring such companies -- say, the ratio of the share price to earnings -- are useless when there is no revenue or profit.

"Investors have a hard time valuing a company like this, where there's tremendous opportunities but no sales yet," said Kathleen Smith, an analyst with Renaissance Capital in Greenwich, Conn. Renaissance specializes in evaluating new public offerings and holds no stake in CyberCash.

Smith said her firm tries to judge such companies by carefully picking similar firms that have already gone public. In the case of CyberCash, Smith looked at the valuation of two other new electronic commerce firms. While one focuses on serving consumers, the other aims to serve businesses. CyberCash hopes to do both.

Checkfree Corp., in Columbus, Ohio, made its stock market debut in late September and now has a market capitalization of more than $700 million. Checkfree offers consumers ways to pay bills via the Internet instead of by paper. Harbinger Corp. of Atlanta, by contrast, principally supports electronic commerce between corporations. Harbinger has reached a market capitalization of $200 million since its initial public offering in late August.

CyberCash, with a market value of about $500 million, has jumped a bit higher than Smith expected. She too attributes the rise to the market's enthusiasm for the Internet.

CyberCash is still in what the Securities and Exchange Commission defines as a "quiet period" related to the stock offering, so company executives were unable to comment publicly on the stock. CAPTION: TAKING OFF (This chart was not available)