The head of the world’s largest pension fund said he is looking beyond the safety of sovereign debt as an era of falling rates forces even the most conservative of investors to rethink playbooks.

Masataka Miyazono, the president of Japan’s mammoth Government Pension Investment Fund with ¥162.1 trillion ($1.5 trillion) in assets, said the fund is looking at a range of foreign debt as it seeks steady returns in pandemic-riven markets after swinging from a record loss to a historic gain in the first six months of the year.

"We’re going to increase the sophistication of our investment, while closely monitoring the risk-return,” Miyazono, 67, said in an interview in Tokyo on Tuesday. "Apart from foreign sovereign bonds there’s also mortgage debt, corporate debt to consider.”