Private markets custodian Alto has agreed to buy Forge Trust from Charles Schwab, creating an independent self-directed retirement investment platform with more than $20bn (£15bn) in assets under custody.

Alto is a self-directed individual retirement account (IRA) custodian that channels retirement savings into private markets.

The deal covers Forge Trust and its parent company, Forge Services. Alto said the combined business would be the largest independent self-directed retirement investment platform in the US, with more than 60,000 IRAs holding private market assets.

The acquisition brings Forge Trust’s alternative asset classes and account types onto Alto’s technology, custody and investment infrastructure, the firm said.

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“The joining of Alto and Forge Trust brings together the best elements of the past, present, and future of private market retirement investing,” said Eric Satz, founder and chief executive of Alto.

“This is the platform that delivers what private market retirement investing has needed.”

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The acquisition comes as alternative assets push further into retail retirement accounts in the US. More than $19.9tn sits in IRAs, yet little of that capital currently reaches private markets, said Alto.

The deal is subject to approval by the South Dakota Division of Banking.

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