Blockchain security startup BitGo is acquiring a digital asset custodian based in South Dakota that holds more than $12 billion in assets.

The firm announced today that it had struck a deal, subject to final approvals, to acquire the Kingdom Trust Company as well as Kingdom Services. The acquisition comes on the heels of BitGo's $43 million Series B funding round in December.

Kingdom Trust, according to its website, serves over 100,000 clients, focusing on institutional-centered custody services as well as self-directed individual retirement accounts (IRAs).

Speaking to CoinDesk, BitGo CEO Mike Belshe positioned the move as one geared toward a growing interest among institutional clients, with the problem of custody (and regulatory compliance) being at top of mind for some of those eyeing the market.

"That wall of institutional money cannot hit until that custodianship is met, and this is the first custodian for U.S. folks," he said. "Going forward, as a new time of investors in crypto comes along — which is asset managers and hedge funds — they don't have the technical depth. They have other skills, and we want to bridge that."

While the business terms of the deal are complete, the sale is still awaiting regulatory approval.

"All the commercial terms are done," Belshe added.

While the terms of the deal are not being disclosed at this time, the acquisition comes after the two companies had worked together for years. Previously, BitGo had provided cold storage for Kingdom Trust's bitcoin, ethereum and other asset holdings, Belshe told CoinDesk. Indeed, both firms had previously partnered with BitcoinIRA to create products around the cryptocurrency.

He also pointed to the U.S. Securities and Exchange Commission's move to explain its concerns with possible cryptocurrency exchange-traded funds (ETFs). Belshe said the Kingdom Trust acquisition could possibly facilitate the creation of cryptocurrency ETFs given the focus on custody, he said.

To further support this possibility, last month, BitGo added strategic investor and outspoken bitcoin ETF advocate Don Wilson as an advisor.