And it gives us some multiples and compares that to a social-media peer:

LinkedIn’s valuation - at 17 times last year’s sales of $243m - will still lag behind that of Facebook in private markets. The biggest social network is valued at 32 times estimated 2010 sales, according to Nyppex, a private share market.

But the FT story has holes, as its short stories typically do. It doesn’t say anything about earnings or growth rates, which is baffling. And nobody, as far as I can tell, reports what LinkedIn’s projected revenues for 2011 will be. That also should have been in these stories.

The Journal’s Evan Newmark, a former investment banker whose good column on IPO bubble dynamics confirms that LinkedIn’s revenue growth is slowing, has some more numbers:

After all, what is the sense in putting a $4.3 billion valuation on a company with slowing revenue growth and zero projected profits for 2011 or in paying $43.50 for a share that post-IPO will have a tangible book value of just of $3.38, or one-thirteenth what you just paid.

Of course, there isn’t much sense. But that doesn’t matter. Here’s what does: The belief that someone out there will pay even more for the shares.

Newmark’s numbers and all the other ones above are based on LinkedIn’s IPO pricing of $45. As I type this, the stock is up a stunning 99 105 122 135 percent in its first couple hours of trading. So all these high multiples from above? More than double them.

LinkedIn is now worth $10 billion on the stock market. Which means it’s trading at 41 times last year’s sales—higher than Facebook’s huge valuation. It has a trailing price-to-earnings ratio of 650 (and remember, it will lose money this year). Newmark’s tangible book value number is now one-thirty-first of its stock price.

Hey—what bubble?

Ryan Chittum is a former Wall Street Journal reporter, and deputy editor of The Audit, CJR's business section. If you see notable business journalism, give him a heads-up at rc2538@columbia.edu.