Palantir is reportedly raising $500 million at a $20 billion valuation, making it the third most valuable US startup

Palantir is raising $500 million at a valuation of $20 billion, according to a report by Buzzfeed on Tuesday.

The new funding would make the secretive data analytics company the third highest-valued startup in the US, after Uber (around $50 billion) and Airbnb ($24 billion). Palantir has raised $1 billion so far, according to Crunchbase.

Founded in 2004, Palantir has the US government and Wall Street financial firms as its clients. Its cofounders include billionaire investor Peter Thiel and Joe Lonsdale, who's now leading the venture capital firm Formation 8.

Despite its high-profile brand, Palantir has remained largely low key with regards with its business. But according to Buzzfeed, its business is growing a strong pace, and it has more than $1 billion in cash on its balance sheet.