Coinbase Global (COIN) shares started the trading day Thursday with a 31% increase to $106, after the cryptocurrency exchange announced a new partnership with asset management giant BlackRock (BLK). Shares were then briefly halted for trading by the Nasdaq for volatility. They were recently trading up 20% to $97.36.

More than 25 million shares of Coinbase were traded in the opening hour of trading, compared with the stock's average daily volume of 15 million shares.

"Calls that crypto is dead have been overdone," said Edward Moya, senior market analyst for the Americas at OANDA. "In fact, crypto is alive and well. BlackRock has partnered with Coinbase to make crypto available to institutional investors. This is much-needed positive news for crypto traders and should provide some optimism for the longer-term health of the cryptoverse."

Oppenheimer reiterated its outperform rating on Coinbase stock on Thursday, writing that "in our view, the BlackRock partnership is another validation of 1) the potential of blockchain/digital assets; 2) Coinbase's reputation, technology, compliance and service capabilities; and 3) the scalability of the Coinbase platform to add more tokens and other services."

The bank noted that BlackRock had $8.5 trillion in assets under management as of the second quarter of this year and that its Aladdin investment platform has more than 200 institutional users.

Coinbase stock has declined more than 60% year-to-date with the onset of the cryptocurrency bear market. Shares dipped in late June as rival Binance.US launched zero-fee bitcoin trading. Coinbase recovered some losses earlier this week after Robinhood reported quarterly earnings results that included a sequential gain in crypto revenue.

The company is due to report second-quarter earnings after the close on Tuesday.

UPDATE (August 4, 14:30 UTC): Added details of trading volume and quote from Moya.

UPDATE (August 4, 15:42 UTC): Added quote and information from Oppenheimer.