Japan???s Government Pension Investment Fund was dethroned as the world???s biggest pool of retirement savings as a depreciating yen eroded the value of its assets in dollar terms.

The fund posted a record gain for the three months through March, generating a 9.5% return, but the yen???s slump to a 38-year low against the greenback was deep enough to put the value of its assets below that of Norway???s wealth fund in dollar terms.