Report: Groupon Worth More Than Twitter; Facebook More Than eBay, Yahoo

The value of Facebook topped first-generation Internet companies eBay and Yahoo over the past six months, while the upstart Groupon overtook Twitter according to NYPPEX, a company that estimates the value of privately held companies.

Facebook’s value rose 56% to an estimated $41.2 billion from June 30 to Dec. 1, based on the prices that private and institutional investors have paid for shares. That puts it above public values of eBay ($36.8 billion), and Yahoo ($21.4 billion). Over that same period, the value of Groupon nearly quadrupled to $4.8 billion, putting it above Twitter, which more than doubled to $3.7 billion.

NYPPEX estimates the value of privately held companies by looking private stock trades in the secondary market; purchases from existing investors and stock-holding employees. The firm believes that the value of secondary transactions will more than double this year as more companies delay initial public offerings, according to Bloomberg.

Along with Facebook, Groupon and Twitter, the firm examined eight other social media companies including business network LinkedIn, gaming companies Zynga and RockYou, Linden Research, makers of the Second Life virtual world, news aggregator Digg, location-based discovery service Loopt, and event sharing service Eventful.