Facebook stock flat after IPO frenzy

Following months of hype and excitement, Facebook's stock was essentially flat after the first day of public trading Friday.

The company's initial public offering price was $38 per share, and the stock closed at $38.23, a gain of 0.6 percent.

The stock, which uses the symbol "FB," was set to open at 11 a.m. but was delayed for about half an hour, possibly because of technical problems.

The stock initially shot up to about $42 early in the day but quickly settled back down to its initial price.

Trading was heavy in the first day, with 505 million shares trading hands, a new record for an IPO.

The stock price values Facebook at more than $100 billion, more than McDonald’s, Disney or Starbucks.  

The company, which Mark Zuckerberg founded in his Harvard University dorm in 2004, now has more than 900 million users worldwide, with about 188 million in the United States and Canada.

But investors may have been worried about the company's ability to squeeze enough revenue out of its users to justify its valuation. Last year, the company's profits were $1 billion, which is small considering its massive user base.

The majority of Facebook’s revenue comes from advertising, but the company has acknowledged that it will need to find ways to better display ads to smartphone users. 

The level of detail Facebook collects on its users has also drawn criticism from some regulators and lawmakers. The company has acknowledged that new privacy regulations could hurt its business model.