Can unprofitable companies go public?

Yes, but it's much better to be in the black.

In the week since car-sharing service ZipCar (ZIP) went public, its stock has climbed more than 60%. Not too shabby for a company whose losses nearly tripled between 2009 and 2010.

The reality is that companies do not need profits to go public.

So far this year, 19 VC-backed companies have priced IPOs on U.S. exchanges. Twelve of them were unprofitable, including yesterday's $92 million offering from Sagent Pharmaceuticals (SGNT).

In general, however, profitable issuers have more successful IPOs and after-market performance. On average, they raised $108 million and were trading 25.23% higher than their offering prices as of yesterday's market close. The unprofitable issuers (minus Sagent, which began trading today) raised around $88 million, and were up just over 9%. That last figure will rise a bit once Sagent is taken into account -- it's up around 19% as of this writing -- but not by too much.

Moreover, the largest percentage gainer is Qihoo 360 Technology (QIHU), a Chinese maker of anti-virus software, which reported nearly $8.5 million in net profit last year on $57 million in revenue. Its shares are up nearly 135% from its $14.50 per share IPO price.

Here's the full list (unprofitable companies in red):

More on Fortune.com:

• Why I'm not buying Zillow
• How RenRen's IPO is setting the table for Facebook
• Zoom, zoom: Zipcar is a $1 billion company!