Are sales of private company shares taking a breather? Demand for private company shares resulted in $115.4 million worth of transactions on SecondMarket during the first quarter of 2011, down from $120 million last year. The value of shares trading hands was also down from $158 million in the fourth quarter of 2010. The most coveted private stock remains Facebook, which saw its valuation reach $85 billion . Facebook was the most "watched" company, followed by Twitter, Groupon, LinkedIn, Zynga, Foursquare, Skype, Pandora, Yelp, and Gilt Groupe—in that order.