How Big Is OCIO Market? At Least $4.79T, per Chestnut Advisory

The global outsourced CIO world is larger than most estimates, according to management consulting firm Chestnut Advisory. The firm estimated in a recent report that OCIO providers worldwide managed $4.79 trillion in 2024,

But why is estimating total OCIO assets under management so difficult?

It’s the lack of standards, Chestnut Advisory writes: Because the industry is relatively new, it does not have industry standards as robust as other industry segments.

One of those standards defines an OCIO mandate. Some OCIO providers report different mandates and client types; some exclusively report institutional mandates; and others include private wealth mandates in their AUM. Some providers include legacy assets the firm did not allocate, while others do not, according to the report.

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“Our definition of an OCIO mandate is similar to the new definition proposed by the CFA Institute 1—an engagement [in which] the OCIO provides both strategic investment advice and investment management services in one engagement for a pool of assets,” the report stated. “This definition includes mandates for asset class sleeves, partial portfolios and full portfolios.”

Chestnut defines an OCIO mandate as an engagement in which a third party provides both strategic investment advice and investment management services for a pool of assets.

“There are many different types of mandates and clients included in the ‘OCIO AUM’ reported by providers today,” said Amanda Tepper, Chestnut Advisory’s co-managing partner, in a statement. “Our new definition of an OCIO mandate is a first step toward establishing an industry standard for OCIO AUM.”

The largest OCIO providers included in the report include Mercer, with $548 billion in outsourced assets under management, Goldman Sachs Asset Management ($392 billion), BlackRock ($367 billion), Russell Investments ($327 billion) and Captrust ($209 billion).

The firm forecasted that the OCIO market will grow to $7.3 trillion in assets under management by 2029.

Chestnut researched the 2024 AUM of 134 different OCIO firms, acknowledging “the AUM values on our list are imperfect” due to the varying standards. The report also stated it expects to include more European and Asian OCIO providers in future rankings.