In 1999, Halvorsen left Tiger to co-found Viking Global Investors, an investment firm managing in excess of $30 billion capital, of which he is currently the CEO, alongside David Ott and Brian Olson. Halvorsen, Ott, and Olson are part of the group known as "Tiger Cubs," former employees of Julian Robertson's Tiger Management Corporation now working as hedge fund managers on their own. Viking Global's main operations cover public equity and hedge funds on the international market.