Steven P. Jobs, who helped start Apple Computer Inc., became a billionaire Wednesday when a small digital studio he bought nine years ago went public to a storm of investor demand.

In its first trading day, investors gave Pixar Animation Studios, the company that made the current No. 1 movie "Toy Story," a market value of $1.46 billion.Pixar's stock, priced by underwriters Tuesday at $22, shot to $46 on its opening trade, reached as high as $49.50 and closed at $39 on the Nasdaq Stock Market.

Jobs, who is Pixar's president, owns 80 percent of its 37.4 million outstanding shares. His net worth reached several hundred million dollars a decade ago when Apple represented the cutting edge of technology. But that was greatly exceeded by the reception for Pixar stock.

The initial public offering had been one of the most widely followed since the debut of Netscape Communications Corp., an In-ter-net software company, on Aug. 9.

It was preceded by a wave of publicity for Pixar - ranging from the cover of "Wired" magazine to the opening week success of "Toy Story," its first major movie.

"Toy Story" is a tale of a child's toys that come to life, especially cowboy Woody and spaceman Buzz, and learn friendship and loyalty. It is the first movie made entirely by computer-generated images rather than hand-drawn animation or filmed action.

Walt Disney Co. distributed "Toy Story," the first of three movies it hired Pixar to create. Some of the investor interest in Pixar is based on that relationship, analysts said.

Pixar, based in Richmond, Calif., is a digital studio that uses computers to make visual images. It used to be a part of LucasFilm, the special effects company of "Star Wars" creator George Lucas.

Jobs bought Pixar from LucasFilm in 1986 and invested millions to build the company's computer systems.

But he is most often publicly associated with Next Computer Inc., which he started in 1985 to build new personal computers. It floundered for several years and eventually limited its scope to software.

Calls to Jobs' offices at both Pixar and Next were not immediately returned.

"It's something between ironic and moronic" that Jobs hit his biggest jackpot with the company where he is the least involved, said David Coursey, editor of PC Letter, an industry newsletter based in a San Mateo, Calif.

"Because the market votes in a certain way, Steve Jobs becomes a billionaire on paper for the company that he's invested in but not associated (by the public) with," Coursey said. "What impresses me about Steve Jobs is that the Macintosh still stands up very well against the best Microsoft can throw at it."

Jobs led development of the Macintosh at Apple back in the early 1980s. The machine is still the cornerstone product for Apple, which is the nation's second-largest maker of personal computers.

Like the recent public offering for Netscape, Pixar received a market value far exceeding what is typical for a company of its size. The company earned $3.1 million on revenue of $10.6 million for the nine months ended Sept. 30.