Will Facebook deliver an IPO surprise?

NEW YORK - Facebook founder Mark Zuckerberg turns up at business conventions in a hoodie. Cocky is the word used to describe him most often, after billionaire. He was Time's person of the year at 26.

So when he takes Facebook public, why would he follow the Wall Street rules?

The company filed to sell stock on the open market in what is likely to be the most talked-about initial public offering since Google in 2004, maybe since the go-go 1990s.

Around the nation, regular investors and IPO watchers are anticipating some kind of twist - perhaps a provision for the 800 million users of Facebook, a company that promotes itself as all about personal connections, to get in on the action.

"Pandemonium is what I expect in terms of demand for this stock," says Scott Sweet, senior managing partner at IPO Boutique, an advisory firm.

The most successful young technology companies have a history of doing things differently. Google's IPO prospectus contained a letter from its founders to investors that said the company believed in the motto "Don't be evil."

Facebook declined to comment, but Reena Aggarwal, a finance professor who has studied IPOs at Georgetown University's McDonough School of Business, believes Zuckerberg will emulate Google's philosophy, at least in principle.

Google founders Larry Page and Sergey Brin wanted an IPO accessible to all investors, and said so in their first regulatory filing. Facebook may say something similar when it files to declare its intention to sell stock publicly.

Facebook hopes to raise $5 billion in the offering. A stock usually starts trading three to four months after the filing.

When it filed for an IPO in June, Groupon, which e-mails daily deals on products and services to its members, added a letter from its 30-year-old founder, Andrew Mason.

"We are unusual and we like it that way," the letter said. "We want the time people spend with Groupon to be memorable. Life is too short to be a boring company."

It has almost become conventional for tech companies to include an unconventional letter when they make their stock-market debut.

In Facebook's case, IPO watchers wonder whether there might be a provision specifically designed to give the little-guy investor, even the casual Facebook user who doesn't invest, a piece of the debut.

"There is a feeling that there will be something unique in store for Facebook users," Aggarwal says.

When most companies go public, they let Wall Street investment banks handle everything, with the sweet ground-floor stock price reserved for big institutional investors.

But that probably won't do for Facebook, created in a Harvard University dorm room eight years ago. Or for Zuckerberg, whose antiestablishment credentials include spurning a $15 billion takeover offer from Microsoft.