A series of sudden and positive developments on the spot ether exchange-traded fund (ETF) sent the price of ether soaring as much as 30% over the last two days. The second largest digital asset was trading at $3,798 at the time of writing, with a daily trading volume of $33 billion.

On Monday, the U.S. Securities and Exchange Commission (SEC) asked spot ether ETF applicants to update their 19b-4 filings ahead of their decision on VanEck’s application due on May 23. This prompted Bloomberg ETF analysts Eric Balchunas and James Seyffart to up their estimates of the odds of approval to 75% from the previously forecast 25%.

That forecast remained intact on Tuesday, after filings from five of the prospective spot ether ETF applicants showed they had amended their 19b-4 forms. VanEck, Fidelity, Invesco/Galaxy, Ark/21Shares and Franklin Templeton all updated their filings.

The most notable change was the removal of provisions for ETH staking by Fidelity, Franklin Templeton and Ark/21Shares. Bloomberg’s Seyffart noted on X that the spot ether ETF is still potentially a long way from a launch, but the filings prove that speculation on the improved odds have been accurate so far.

According to a report from Barrons, SEC staff told exchanges that the regulator is “leaning towards approving spot ETH ETFs” and that if comments on the applications are resolved in time, approvals could take place as early as this week.

The renewed optimism around a spot ether ETF also sparked significant inflows of ETH onto crypto exchanges. Data from Nansen, shared on X by Anagaram partner David Alexander, shows that 87,800 ETH worth $327 million was sent to exchanges since the speculation around an imminent approval for the ether based funds began.

“This is easily the highest level of daily ETH inflows to exchanges since January and marks the third consecutive day of net inflows. In total, more than 122,000 ETH has been sent to exchanges during this time,” said Alexander.

ETH also finds itself in the spotlight among derivatives traders, with data from CryptoQuant also showing that open interest for ether hit an all-time high of $10.5 billion on May 21. 

However, the biggest winners in the game of betting on the likelihood of an ether ETF being approved by the end of May were participants in Polymarket’s prediction market. Data shows that the ‘yes’ trade surged 550% from paying 10 cents to 65 cents.