"You will probably see hundreds, if not thousands, of newly minted millionaires in the next two or three years," said Steve Eskenazi, a tech investor in Hillsborough, north of Palo Alto, where the minimum lot size is a half acre (0.2 hectare). He sold his portion of an online advertising network to Sunnyvale-based Yahoo! Inc. in 2007.

"Most people in their 20s who find themselves millionaires feel it's their inalienable right to buy real estate, and they're typically not price sensitive," Eskenazi said.

Zuckerberg Purchase

Facebook founder Mark Zuckerberg, 27, bought a house this year in Palo Alto, said Larry Yu, a company spokesman. He declined to disclose details. Zuckerberg paid $7 million for a 5,000-square-foot (465,000-square-meter), seven-bedroom home in a "leafy and affluent" neighborhood, the San Jose Mercury News reported May 5, without saying where it got the information.

The purchase came ahead of Facebook's scheduled move to Menlo Park, just north of Palo Alto.

As more firms go public and workers cash in shares, real estate within 15 miles (24 kilometers) of the office will climb, said Rosen, who gave a presentation at Google Inc.'s Mountain View headquarters before the company's 2004 IPO to educate employees on housing. Sales are usually concentrated in the "middle to upper end," he said.

In Cupertino, about 12 miles from Palo Alto, a three- bedroom home listed for $908,000 got more than a dozen offers and sold for $950,000 on June 8, said Albert Kao, an agent at Giant Realty Inc. in the city. The prior owner, who bought the property in 2002, decided to sell after her children graduated from the public schools. She made a $290,000 profit before commissions, Kao said.

Groupon, Zynga

Groupon Inc., an online coupon provider based in Chicago, filed for an initial share sale June 2 and is hiring engineers in California, according to its website. As early as March, Groupon was in talks with bankers about an IPO that would value the company at as much as $25 billion, two people familiar with the matter said at the time.

Zynga Inc. of San Francisco, the largest maker of games for Facebook and valued at $8.8 billion on SharesPost, may file for an IPO by the end of the month, a person with knowledge of the matter said June 3.