Not unusual for highly hyped IPOs to "pop". Underwriters and the first tier of investors like to structure IPO pricing this way so they get a guaranteed exit on the initial craze to buy and beat out subsequent buyers.

Facebook IPO'd at $38, popped up to $45, closed at $38 on the first day, then plummeted down to $27 a week after the IPO. Now its at $107. Anything can happen.

These days, you "have to" leave money on the table, or your IPO is deemed a "failure" (see: Facebook).

I actually don't know the answer to this - but is the situation as straightforward as: "they left money on the table today, but it's in the effort to improve perception and health of the company - and they will be able to sell more down the road with the boost of momentum and health of the stock performance from IPO. At that point, they can capture the value created by an event like today (where they purposefully leave some money on the table) for the move to be net-net positive?

Don't forget that the first day is reserved for enthusiasts and people highly engaged in speculation with the hopes to get on the "ground floor" of something big. Small float, everybody who matters is still under lock-up.

Here's another IPO that went up 56% the first day http://techcrunch.com/2014/12/11/lending-clubs-ipo-pops-56-i... and Google Finance tells a rather somber "where are they now" story.

Yes. The investment bankers and mutual fund companies fucked Square for $100M. The difference between this and other IPOs is that Square is undercapitalized at this point and needs the cash, so the 100M would have gone a long way.

Basically yes, you are selling for X something that the market is willing to buy at 1.6X, however someone must have made a lot of money on that spread today.

My impression is that the media event of an IPO is higher valued than the money