Palantir Technologies (NYSE:PLTR), the data analytics company backed by Peter Thiel, went public on Wednesday when its shares began trading on the New York Stock Exchange.

The company provides analytics for both corporate and government clients but is perhaps best known as a vendor to government spy agencies. It went public via a direct listing instead of an initial public offering. The company's existing shareholders as of Tuesday were able to sell part of their holdings on the New York Stock Exchange, with the stock initially pricing at $10 apiece around 1:30 p.m. EST.

Based on the 2.17 billion shares outstanding Palantir listed in its registration statement, the company's initial market valuation was about $21.7 billion. Palantir last raised private capital in 2015, selling shares at a price that valued the business at $20.3 billion.

Graphic of a secure network.

Image source: Getty Images.

The company, though secretive, has attracted a lot of attention for its technology. And Theil's strong reputation as a co-founder of PayPal and an early investor in both Facebook and Microsoft's LinkedIn helped draw attention to the listing. 

But Palantir also has attracted a number of critics due to its ties to U.S. spy agencies and its work with U.S. immigration agencies. CEO Alexander C. Karp in a letter to investors that was part of the registration statement likened Palantir to a defense contractor and was unapologetic about who uses its technology.

"Our software is used to target terrorists and to keep soldiers safe," Karp wrote. "If we are going to ask someone to put themselves in harm's way, we believe that we have a duty to give them what they need to do their job."

Some critics have also expressed concern about Palantir's governance. The structure of the offering gives Thiel, Karp, and co-founder Stephen Cohen a special class of stock with outsized control, limiting the influence of investors buying the shares trading on the exchange.