Investors who missed out on Facebook's IPO last year may have another chance to get in on the action.
Just one day before joining the S&P 500 index, Facebook founder Mark Zuckerberg and other shareholders announced plans to sell 70 million shares in a secondary offering.
"We think it makes sense considering the stock's performance year-to-date," said Youssef Squali, Internet analyst at Cantor Fitzgerald. Squali also said it looks better when a company sells along with its shareholders as opposed to shareholders selling alone.
Earlier this week, Facebook announced plans to test video ads that play automatically in the mobile and desktop news feeds.
—By CNBC's Christina Medici Scolaro.
Disclosure: Youssef Squali does not own shares of Facebook.