Microsoft

Steve Ballmer tried to buy Facebook outright in 2007 for $15 billion, but Mark Zuckerberg wasn't interested. Instead, Microsoft's CEO scored a deal in which Microsoft invested $240 million for a 1.6 percent stake. Microsoft cashed in $249 million at the IPO but still holds 26.2 million Class B shares. The company wants to do more, not less, with Facebook, so it seems unlikely that cash-rich Microsoft will start selling.