On-demand car service Uber this afternoon announced that it has raised $1.2 billion in new private equity funding at an $17 billion pre-money valuation. For context, Hertz Global Holdings HTZ has a current market cap of just $12.5 billion.

All of the new money is primary capital, meaning that none will be used to cash out existing shareholders or company employees. In a blog post, Kalanick also said that Uber is planning to soon close on another $200 million, bringing the round total of to $1.4 billion (it is not clear if the extra money also will be primary) and the post-money valuation up to $18.4 billion.

CEO Travis Kalanick referred to this valuation as “record-breaking” last week during a conference appearance, but Fortune has confirmed that Facebook FB raised more money in late 2010 and early 2011 at a higher valuation from DST Group and Goldman Sachs GS .

Uber did not identify its new investors, with Kalanick just writing that new backers include “institutional investors, mutual funds, private equity and venture capital partners.” Bloomberg reports that Fidelity Investments led the round, while other new investors included Wellington Management, Summit Partners, BlackRock Inc., Kleiner Perkins Caufield & Byers.

Summit Partners confirmed its participation, with a spokeswoman saying: “Uber’s growth so far is stunning, but we still think this business is still in its early stages relative to the global opportunity to move local transportation from a private car model to a service model.”

Uber last raised money less than a year ago, when it scored $361 million at a $3.4 billion pre-money valuation led by Google Ventures GOOG and TPG Capital. Earlier backers include Benchmark, Menlo Ventures and First Round Capital.

This funding seems, in part, designed to put enormous pressure on rival Lyft, which only has raised around $330 million, most recently at a reported valuation of just under $1 billion.