Coinbase Global on Thursday posted its first quarterly profit since 2021 on sturdy trading volumes due to a resurgence of interest in crypto, sending its shares up nearly 13% after the bell.

Investor enthusiasm for crypto was rekindled in recent months by the U.S. Securities and Exchange Commission's (SEC) highly anticipated approval of the first spot bitcoin exchange-traded funds (ETFs).

While the ETFs were approved only in January, expectations of a favorable decision by the SEC propelled bitcoin's price 57% higher in the last three months of 2023.

That drove a 64% jump in crypto exchange Coinbase's transaction revenue to $529.3 million in the fourth quarter.

"Results this quarter were exceptional as they far exceeded both our expectations and Street consensus," said Michael Elliott, equity research analyst with CFRA Research.

The crypto exchange now expects a strong first quarter for its subscription and services unit, which houses businesses other than trading.

It forecast revenue from the unit between $410 million and $480 million, higher than LSEG estimate of $356.22 million.

In the fourth quarter, revenue from the unit jumped nearly 33% to $375.4 million, with the biggest boost coming from stablecoin revenue - the interest that Coinbase earns from its partnership with fintech firm Circle.

Circle issues the USD Coin (USDC) stablecoin that it jointly governs with Coinbase. The interest on reserves backing USDC are a major source of revenue for Coinbase, which has been able to pocket higher income because of the Federal Reserve's interest rate hikes.

Overall, the company reported a profit of $273.4 million, or $1.04 per share, in the three months ended Dec. 31, compared with a loss of $557 million, or $2.46 per share, a year earlier. Analysts had expected a loss of 1 cent per share, according to LSEG data.

Elliott said he had longer-term concerns that "the spot ETFs may lead more investors to look for crypto exposure off the Coinbase platform."

But the company brushed aside such concerns.

"ETFs have just been net positive for the industry and additive to Coinbase," CFO Alesia Haas said.

(Reporting by Niket Nishant and Sri Hari N S in Bengaluru; Editing by Shinjini Ganguli and Anil D'Silva)