Iwi are too reliant on investments in property and primary industries, restricting returns for their members, according to a new report.
The annual Iwi Investment Report by consulting firm TDB Advisory, showed the country's eight largest iwi with a collective $9 billion worth of assets, had weak growth in the 2019 year.
Six of the iwi reported lower returns, while only two, Ngāpuhi and Tūhoe, reported gains, albeit of less than 2 percent.
"They like to aim for what they call low-to-medium risk, but I think for some of them, if they looked really hard at their portfolio, they might find it is actually more risky than they would ideally like," TDB Advisory director Philip Barry said.
"It does come back to diversification, they are typically quite exposed to a few sectors."
Ngāi Tahu, Ngāpuhi, Ngāti Awa, Ngāti Whātua Ōrākei and Waikato-Tainui were invested in mostly property and primary industries, including fishing or forestry.
Ngāti Porou, Raukawa, and Tūhoe invested mostly in managed funds, while all of the iwi had taken steps to invest in public or private companies.
"While some of these recent investments are yet to provide high returns, some appear to offer promising opportunities for iwi to increase their returns and asset bases in the future," the report said.