Hard to believe but it’s true. Facebook shares priced exactly one year ago today at $38 a share, giving the social media behemoth a market value of round $104 billion. (“Pricing” is when the company gets the money and the investment bank gets the shares, which it then turns around and sells to stock-market investors.) Today, with shares fluttering around $26.40, the enterprise is valued at around $64 billion. That means that in Facebook’s first year, some $40 billion in market value was vaporized, a remarkable accomplishment of sorts. Here’s how Zuckerberg & Co. managed it.