Palantir Technologies, an ultra-secretive that data analytics and security startup that helps government agencies track down terrorists and uncover financial fraud, has just raised $800 million, according to a filing from the U.S. Securities and Exchange Commission on Wednesday. 

Launched in 2004, it's difficult to still call Palantir a startup. It employs around 2,000 people and is currently valued at $20 billion, up from $15 billion a year ago, making it the fourth most highly-valued tech startup in the world behind Uber, Xiaomi and Airbnb, reported CNBC. However, much like a startup, it's still taking on sums of equity investment and has yet to go public.  

Currently, it stands as the most secretive firm in Silicon Valley, with clients including the U.S. Federal Bureau of Investigation and the Central Intelligence Agency. It has even been rumored that the company provided the data that led to the finding and subsequent killing of Osama bin Laden. 

This news comes after it was widely reported that the startup had raised $129 million in it's latest round of funding. However, when the company opened its latest round, the 11th for investors, money kept pouring in until it eventually reached its current figure.

In total, Palantir has raised close to $2 billion and has bucked skepticism among late-stage investors about investing millions into highly valuable companies. Similar companies in the past have managed to clear the $1 billion valuation mark, only to watch it come under heightened scrutiny, reported Reuters.

Going forward, it's unclear what Palantir intends to do with the money raised, but it's likely it will use the money to further develop its technology.

Palantir was co-founded and backed by billionaire Peter Thiel, the co-founder of PayPal, an early investor in Facebook and a partner at Founders Fund, another venture capital firm investing in technology companies.