Anyone investing in an IPO (or a private company for that matter) looking for a “pop” is trying to predict short term market behavior. That’s just fine, but it’s a high class form of gambling. Investing is risky business, particularly when it’s based on factors that are impossible to understand. I’m guessing that many of those IPO investors are bullish on Facebook’s future. Any company that controls online distribution for nine hundred million people and counting has got to be pretty valuable. I’d put my money on that.