Another day, another record across the booming world of Bitcoin ETFs – fueled by fear of missing out on the latest crypto rally.

BlackRock Inc.’s iShares Bitcoin Trust (ticker IBIT) netted $612 million Wednesday in its biggest one-session haul, breaking a record set just a day prior, data compiled by Bloomberg show. Altogether, the 10 new exchange-traded funds investing directly in the world’s biggest cryptocurrency took in a net $673 million, even with the outflows seen by Grayscale Bitcoin Trust (GBTC). The cash pouring into the funds handily beat their launch day record of $655 million set on Jan. 11.

As Bitcoin surges past $60,000 and on toward new highs, the rush of money into the ETFs, particularly BlackRock’s IBIT, helps explain the digital asset’s remarkable run this year. At the crux of the rally is basic economics: supply and demand. Ever since the spot Bitcoin ETFs were launched last month, demand for the token has outstripped the amount of the cryptocurrency that long-time holders are willing to sell.

Bitcoin has already surged more than 40% this year, driven in part by the successful launch of the ETFs, and making it a top performer across all asset types. Just as proponents of the spot ETFs predicted would occur, last month’s arrival of the new products has kicked open the door to fresh investment, giving the institutional and retail traders a new and easier avenue for sinking capital across the asset class. The interest is evident from the traded value within the group — excluding Grayscale’s fund — as it doubled to over $6 billion with IBIT comprising more than half.

“A sharp correction around about now would be healthy to shake out some of the froth,” said Noelle Acheson, author of the Crypto is Macro Now newsletter. “It’s way too soon in the cycle for the market to be really frothy.”

Buying a share of a spot Bitcoin ETF does not directly impact the cryptocurrency’s price in real time. But the new Bitcoin issuers eventually need to purchase physical Bitcoin in order to hold enough tokens to back the shares they issue. The term “spot” after all implies that issuers have to hold physical Bitcoin rather than a derivative tied to the token.

Further underscoring the demand, IBIT is at the cusp of hitting the $10 billion asset mark in just seven weeks — the fastest an ETF has ever hit such a milestone — according to Bloomberg Intelligence. For context, the $54 billion SPDR Gold Shares (GLD) launched in 2004, which Bitcoin funds are often compared to, took over two years to hit that level.

Despite ETFs being widely available to the masses, there are still some hold-outs. A few large, traditional firms have said they still need to be convinced that the ETFs are worthy additions to their massive trading platforms while others, including Vanguard Group Inc., have flat out to refused to offer the new ETFs on their platforms.

Others though have capitulated. Bank of America Corp.’s Merrill arm and Wells Fargo & Co.’s brokerage unit are offering access to Bitcoin ETFs to some clients upon request, Bloomberg reported.

“There is growing appreciation for the fact that access to the new nine has yet to be fully built out,” wrote Stephane Ouellette, chief executive of FRNT Financial, an institutional platform focused on digital assets. Digital asset investors are speculating on just how broad demand will be once the Bitcoin ETFs are more widely available, he added.