Share of Coinbase soared by 40% on Thursday after the crypto exchange announced a partnership with BlackRock to provide its clients access to cryptocurrency trading, beginning with bitcoin.

Coinbase Prime services will be available to clients of BlackRock’s portfolio management platform for institutional investors, Aladdin. It will provide crypto trading, custody, prime brokerage, and reporting capabilities. BlackRock is the largest asset manager in the world with more than $8 trillion under management.

Coinbase shares have been on a tear lately and analysts have not been sure why. The stock jumped 20% on Wednesday. The shares were still down nearly 70% for 2022 through Wednesday’s close.

The unusual jump in Coinbase this week could be related to investors who were betting against the stock scrambling to cover their short positions, a so-called short squeeze. More than 22% of Coinbase’s shares which are available for trading are sold short, according to FactSet. So as the stock has run, these investors have to buy back the stock to cover their losses, further fueling the gains.