So many employees showed up for the festivities, that the main headquarters reached capacity shortly after 6 a.m.
[Ads /]
RELATED: Here's what you need to know about Pinterest's IPO
The overflow crowd was diverted to another building in time to watch the opening bell ring. The digital scrapbooking company is trading on the New York Stock Exchange at $19 a share for a $12.7 billion valuation. Shares are trading under the ticker symbol PINS.
Last week, Pinterest expected to sell 75 million shares priced between $15 and $17. The price was upgraded to $19 by Thursday morning. Some analysts believe $19 is too high.
Ian Sherr, the executive director of CNET, talked to ABC7 News about Pinterest's pricing in early April.
RELATED: IPO 'tidal wave' expected to drive up San Francisco home prices
"You think of Facebook and Twitter and all of these companies that have like their CEO's on the covers of the glossy magazine covers and everything," Sherr said. "Pinterest doesn't play that game. They're very quiet. They kind of stay subdued. So, in a lot of ways, this is not surprising.
[Ads /]
They're not trying to make a big blowout start for their time on Wall Street. Maybe the shares will go up, or they'll go down, but they're not being aggressive with their pricing."
Pinterest is a burgeoning company and also losing money. It has more than 250 million users and had a revenue of $750 million last year. Their losses aren't nearly as steep as peers like Lyft or Uber.
"We're talking about hundreds of millions being lost by them," Sherr said. "Pinterest only lost a little less than $100 (million) last year. It's actually less than they lost the year before. So, they're showing they're growing the numbers of users they have, and also pairing back losses."
Pinterest raised $1.6 billion dollars from big investors in the offering.
See more stories on Pinterest.