Established in 2005, the QIA made a big international splash by snapping up trophy assets. It made headlines again in December by taking a strategic stake in Rosneft. But the oil price drop has also prompted a strategy overhaul, with the fund starting to take a more diversified approach to investments.

True to form, the Qatar Investment Authority (QIA) generated headlines worldwide in December 2016 when it helped close one of the biggest oil deals of the year through its strategic...