Mark Zuckerberg's desk at Facebook HQ

According to a report from Bloomberg, Facebook is planning to stop trading shares in secondary markets sometime in the beginning of April. This news comes just two months after Facebook filed a $5 billion initial public offering (IPO) to begin trading shares. The world's largest social network, however, never gave a timeframe of the timing of the IPO. It's been rumored to be sometime in May of this year, but with this news, it could come even earlier.