Like the online banking software it makes, InteliData Technologies Corp. of Reston is pretty close to invisible.

Installed deep inside the mainframe computers of big banks, InteliData's product functions as a faceless factotum, processing transactions for customers who never know that the company's software is at work.

Nor does InteliData's stock get much notice. Analysts have abandoned coverage of both the company and its biggest shareholder, WorldCorp, whose stock has fallen to 2 cents a share since it filed for bankruptcy reorganization last winter.

But somebody must be paying attention to InteliData, because its stock has jumped 70 percent in the last week as the company signed up the first clients for the improved version of its system. The shares closed yesterday at $4.37 1/2, up 42 cents for the day and almost $2 since last week.

The bump is the best thing that's happened to InteliData stock since last April when the announcement of a possible merger with Home Financial Network kicked the shares from around $1 to more than $5. The stock dove back to $2 after the merger was called off because of accounting complications that made it unattractive financially, though appealing strategically.

At the time, the two companies said they would work together, packaging Home Financial Network's software, which is used by customers who bank at home, with InteliData's internal processing software.

That cooperation has produced its first two big jobs--an Internet banking and bill-paying system launched this week by BB&T Corp. and a similar package coming soon for BancWest Corp., which owns First Hawaiian Bank and Bank of the West, headquartered in California.

BB&T is the first bank to use the combined InteliData/Home Financial Network system; BancWest is the first to hire InteliData to run its system rather than simply buy the software.

The two contracts not only show that InteliData can provide a complete home banking package for multibillion-dollar banks--without the need for other vendors--but also that the company can both install and operate home-banking systems, said communications director Rob Borella.

By switching from software maker to service company, InteliData hopes to generate an ongoing stream of revenue, which would stabilize the company's finances and help revive analyst coverage, Borella said.

Until the company regains regular research, however, InteliData's stock will be driven by the invisible winds of Wall Street. In the last week, the market has been whispering "Internet play" and wafting the stock upward. But if short-term traders who have made quick profits in the stock decide it's time to take their money, the updraft could be followed by a great sucking sound.

CAPTION: InteliData (This chart was not available)