Twitter wasn’t the biggest IPO of 2013. You haven’t heard of the company that was.

by Lydia DePillis

It's December, which means it's about time for recaps of the year that was! Let's start with the market for initial public offerings, since we can basically see through to the end of 2013 -- barring last-minute entrants and any secret filings we may not know about, the companies that have started their road shows will be the rest of it.
By all objective measures, 2013 has been a big year for IPOs. The proceeds raised this year surpassed 2012's total in early November, putting it on track to match 2007, the highest year since the tech bubble. Market exuberance has helped even small, relatively simple companies like Potbelly's and the Container Store to debut with large jumps in their stock prices.
So which ones were the biggest?
Well, one is yet to come. In a few days, the Blackstone Group will offer the hotel chain Hilton Worldwide to the market again, after having taken it private for $26 billion in 2007. The IPO is expected to raise around $2.4 billion, which is a lot of money, and the prospect has been generating some interest because of the nature of Hilton's business model -- it mostly doesn't own hotels anymore, but rather just makes money by licensing its brand and operating properties that belong to others.

But that will just be the second biggest of the year, according to Renaissance Capital. You probably haven't heard of the ones that come before and after it.
Number three was Zoetis, the world's biggest animal health company, which raised $2.24 billion when Pfizer spun it off in January. It's expected to dominate the $22 billion market for products to keep pets and livestock alive and well. Number one was Plains GP Holdings, an oil and gas distribution company that operates pipelines. It raised $2.82 billion in mid-October, cashing in on the domestic energy boom that's fueling much of the country's economic growth.
Number four was Twitter, which you've heard about. It raised $1.82 billion, which is pretty good for a six-year-old social app. The publicity accompanying that IPO, though, was enormous: A Nexis search for "Twitter" and "IPO" in the month before and the day after the actual event yields 2,017 hits.
A similar search for Zoetis yielded 52 mentions. And Plains GP Holdings? A grand total of five.
It's not hard to understand why there would be less public interest in a giant oil logistics company that was also basically a division of an even more giant oil company spun off for the purpose of maximizing returns to existing investors. And of course, the mainstream media is obsessed with Twitter perhaps more than any other private enterprise.
But it's still a little remarkable that in a year when the general public was immersed in the mechanics of a very buzzy IPO, where terms like "S1" and "road show" entered the popular vocabulary, we could have entirely ignored one that was a billion dollars bigger.