Every five years, Japan’s Government Pension Investment Fund sends a frisson of excitement through the investment community. This is one such year: when the country’s largest fund conducts a quinquennial review of its investment assumptions — encompassing everything from inflation to expected returns for various asset classes.

These decisions determine the ￥246tn ($1.6tn) fund’s policy portfolio and how much money goes to which asset classes. It may also have an impact on how much will go to each of its 39 outside fund managers and whether that list may expand.

Established in 2006, GPIF was set up to manage part of Japan’s national public pension and its reserves, and to create enough investment growth to meet the needs of the country’s rapidly ageing population. Since 2014, the fund has held roughly half its assets in equities and half in fixed income instruments, both split between domestic and overseas holdings.