The board of CalPERS has approved a momentous structural change that gives the $556 billion fund a single reference portfolio for judging performance, delegated authority to investment staff to construct the portfolio, and a simplified measure of success.

The fund’s chief investment officer, Stephen Gilmore, has been behind the fund’s shift to this approach which he says can add 50 to 60 basis points to portfolio returns.

In a long and detailed interview, Top1000funds.com editor Amanda White spoke to Gilmore about how a TPA mindset can add value, simplify accountability and open new opportunities for investments.