Airbnb’s valuation set to reach $13 billion after employee stock sale by Laura Lorenzetti @FortuneMagazine 9:37 AM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons Airbnb is prepping an employee stock sale that would end up boosting the startup’s valuation to $13 billion, up from $10 billion earlier this year. That would make the online rental site the second most valuable private company in Silicon Valley, with only private-car service Uber worth more, reported the Financial Times. Airbnb CEO Brian Chesky, who topped Fortune’s 40 under 40 list this year (coincidentally tied for the top spot with Uber CEO Travis Kalanick), has been expanding the site amid unclear regulations worldwide. New York City recently said it would crack down on the service, which is in murky legal territory locally. At the same time, San Francisco put legislation forward that would legitimize and regulate Airbnb and other non-traditional hotel options. The company is letting employees cash in on some of their stock and talking to existing investors about potentially buying back large potions of shares. Airbnb may offer investors tens of millions of dollars worth of buybacks. Those funds would then go to employees, not towards new capital for the company, sources told the FT. Airbnb closed a $475 million funding round in July which valued the company at $10 billion at the time. Sequoia Capital and Andreessen Horowitz, a longtime investor in the company, both participated in the round. Uber, the top valued private startup in the Valley, became worth $17 billion this summer after a $1.2 billion funding round.