State of Wisconsin Investment Board, Madison, earned a -1.7% return on its $65.7 billion core fund during the first five months of the year, underperforming its customized benchmark's return of -1.5%, according to a statement by board officials.
Its $4.7 billion variable fund returned -3.1% in the same period, outperforming the customized benchmark return of -3.2%.
The core fund is allocated to domestic and international equities, fixed income, real estate and private equity, while the variable fund is allocated exclusively to domestic and international equities.
Some 20% of the Wisconsin Retirement System's members voluntarily participate in the variable fund, electing to put half of their contributions in it, instead of all their contributions in the core fund.
The board had $76.2 billion in total assets as of May 31.