Facebook Sends the Lockup Expiration Bears Packing

PO lockup expirations just ain't what they used to be. Back in my day, a bottle of soda cost just $0.15, we used to have to ride our horses to work through six feet of snow, and freshly public companies facing a lockup expiration were destined to tank.
Nowadays, that last bit of formerly accepted wisdom doesn't quite pan out as reliably as it used to. In August, Yelp (NYSE: YELP  ) shares skyrocketed by 25% the day its lockup restrictions on insiders expired. That made me feel rather silly since I figured shares would tank once early investors were permitted to flood the market.
Well, the same storyline played out today for Facebook (NASDAQ: FB  ) , with shares jumping by as much as 11% on its own IPO lockup expiration. Is the lockup expiration sell-off a thing of the past?