US financial technology firm Acorns will allow customers to use its app to invest up to 5% of their portfolio in bitcoin via an exchange traded-fund, in response to increasing interest from users of cryptocurrency, the company said Tuesday.

The Irvine, California-based company will offer bitcoin exposure to users through the ProShares bitcoin exchange-traded fund (ETF), which began trading in October as the first US bitcoin futures-based ETF.

Retail brokers and robo advisers including Robinhood Markets Inc, TD Ameritrade and Wealthfront have started to offer customers exposure to cryptocurrencies over the past several years either through direct trading or investment vehicles as popular interest in such digital assets has surged.

Acorns will determine what percentage of a customer’s portfolio can be put in bitcoin based on their investment profile, which includes age, income and overall financial goals.

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That percentage ranges from a conservative 1% exposure to an “aggressive” 5% exposure, Acorns’ chief executive officer, Noah Kerner, said in an interview.

“We’re really trying to drive home the philosophy of diversification and the principles of long-term investing,” he said.

Kerner added that about two-thirds of Acorns’ 4.6 million subscribers across the United States said they had not invested in crypto because of a lack of understanding as to how digital currencies work, as well as the volatility associated with the asset class.

“Something like bitcoin or any volatile asset class, it’s fine and sensible to have exposure to it, but it should be through the lens of a balanced portfolio,” Kerner said.

Earlier this month, Acorns notched a valuation of $2 billion after raising $300 million in a funding round led by buyout firm TPG. The company scrapped a proposed merger with a special- purpose acquisition company in January, citing market conditions.