Credit Suisse has struck a partnership with Palantir, one of Silicon Valley's most secretive start-ups, to stop rogue traders, the companies said this week.

The 50-50 joint venture, called Signac, will focus on catching unauthorized trading, with the aim of expanding the software and technology to monitor rogue behavior across the bank worldwide.

Palantir uses so-called big data – massive data sets that can be analyzed by computers to reveal trends and hopefully lead to better decision-making – and applies it to areas ranging from defense to fraud.

The company is valued at $20 billion after raising fresh funds last year, making it the fourth most highly-valued tech start-up in the world behind Uber, Xiaomi and Airbnb. Among its investors is In-Q-Tel, the CIA's not-for-profit venture capital firm that invests in technology companies in order to support U.S. intelligence agencies. The start-up was co-founded by Peter Thiel, who was also a co-founder at PayPal.