Who’s buying Facebook stock, the CEO that thinks Dropbox is overvalued, Tumblr’s growing pains, and more from today’s TechCrunch Disrupt. Which companies should Yahoo acquire next? What’s the secret to a successful start-up ecosystem in New York city? When is Facebook stock worth the buy? Which companies should Yahoo acquire next? What’s the secret to a successful start-up ecosystem in New York city? When is Facebook stock worth the buy? These were just a few of the big questions discussed this morning at TechCrunch Disrupt in Manhattan’s Pier 94, a cavernous former ship terminal (complete with draft and sparrows flying overhead) that functions this week as the event’s home. Monday’s panels and presentations consisted of a veritable who’s-who of the tech and start-up world—with a big focus on the growing New York City start-up scene. On the investment side, Fred Wilson and David Tisch chatted about Facebook’s IPO and New York City innovation. Jason Goldberg, the founder of Fab.com, said he wants to create the next Ikea—not just the next Zappos-sized company. Michael Arrington said he’ll be buying Facebook stock today. And Brad Garlinghouse, a former executive at AOL, admitted to hearing rumors that Arianna Huffington was almost fired from The Huffington Post. Gossip or real, it is up to you to believe!