One of Britain’s largest retail investment platforms is making a sharp about-face on digital assets. Hargreaves Lansdown, which less than a year ago publicly declared that Bitcoin did not qualify as an asset class, has begun rolling out trading in cryptocurrency exchange-traded notes to roughly 2 million of its customers.

The launch, reported by the Financial Times, starts with nine ETNs tied to Bitcoin and Ether, the two largest cryptocurrencies by market value. The products come from a roster of established issuers including BlackRock, WisdomTree, 21Shares, Invesco, CoinShares, and Bitwise, with annual fees ranging from zero to 0.35 percent.

For a platform that stood alone among major UK brokerages in refusing to offer crypto-linked…