Asset management giant BlackRock on Thursday officially filed for a spot ethereum exchange-traded fund (ETF), doubling down on its cryptocurrency bets amid investor optimism about the approval of such investment vehicles.

The iShares Ethereum Trust, which was registered last week and will be listed on Nasdaq if approved, will give investors access to ether - the second most popular cryptocurrency - without directly owning it.

BlackRock is proposing to convert the trust to a "spot" ETF, which means it will own ether instead of futures products tied to the crypto token.

While futures-based crypto ETFs have previously been approved by the U.S. Securities and Exchange Commission (SEC), the regulator has long contended that the spot crypto market is prone to fraud and manipulation.

But in August, a federal appeals court ruled that the SEC was wrong to reject an application from digital asset manager Grayscale Investments to create a spot bitcoin ETF.

The landmark victory for Grayscale has prompted a wave of enthusiasm among companies that filed for such investment vehicles in recent months, and has helped restore some faith in the crypto industry after it was shaken by several high-profile collapses last year.

BlackRock dipped its toes in the crypto space with its filing for a spot bitcoin ETF in June. Its latest filing indicates that the Wall Street behemoth is aiming to move beyond bitcoin, the world's most popular cryptocurrency.

The company will be vying with crypto natives such as Grayscale and Valkyrie and traditional finance giants like Invesco for market share.

Coinbase Custody, a unit of crypto exchange Coinbase , will hold the proposed ETF's ether in custody. The company is also the proposed custodian of BlackRock's bitcoin ETF.

BlackRock did not immediately respond to a request seeking additional comment.

(Reporting by Niket Nishant in Bengaluru; Editing by Shinjini Ganguli)