NSW Treasury Corporation chief investment officer Stewart Brentnall will retire from full-time employment within the next 12 months, ending a tenure of almost a decade in which he built and embedded the total portfolio approach across the roughly $125 billion the fund manages on behalf of the NSW Government.

TCorp chief executive Rob Kenna said Brentnall, who joined the organisation in March 2017, had “played a pivotal role in the development and implementation of TCorp’s total portfolio approach investment model and its successful application to client portfolios”.

“Together with the investment leadership team, he has helped deliver strong investment outcomes that have exceeded clients’ objectives,” Kenna said.

A comprehensive search for Brentnall’s successor will be undertaken, with an appointment expected to be finalised in the first half of 2027. Brentnall will continue to lead the investment team through the transition, Kenna said, “maintaining his focus on delivering strong investment outcomes for clients and supporting an orderly succession process”.

Brentnall was TCorp’s first chief investment officer, appointed in February 2017 to a role created after the 2015 merger of TCorp with State Super and icare investment functions formed a $70 billion institutional investor. He joined from ANZ Wealth, where he had been CIO.

In 2018 he led a wholesale reorganisation of the investment team, centralising portfolio construction and manager selection. By 2022 TCorp had merged its three underlying investment clients into a single total portfolio investment model, which Brentnall described as a bottom-up, risk-factor based approach in which all investment opportunities compete for capital.

The most significant late-tenure reform came in 2024 with the OneFund restructure. Brentnall told Investment Magazine’s Fiduciary Investors Symposium in Healesville that the new structure, which cut TCorp’s portfolios from 15 to 10, was expected to deliver an additional $400 million to $450 million in investment returns to the NSW Government each year – “a tiny bit of alpha, but 99 per cent of it will be beta”.

Brentnall has been a consistent advocate of scenario-based portfolio construction over forecasting. “Our mantra has become ‘it is much more important to prepare rather than predict’,” he told Investment Magazine in 2022. He was also a vocal critic of peer-relative investing, once likening Your Future Your Super-constrained funds to an English fox hunt, “with dogs following each other’s tails, while not knowing where the pack is going”.