The first U.S. ETFs that directly hold Bitcoin are off to a strong start, with billions of dollars changing hands in a historical first day of trading for the long-sought investment vehicles. 

Over US$3.5 billion shares have traded between the 11 U.S. spot Bitcoin exchange-traded funds as of 1 p.m. in New York on Thursday. The Grayscale Bitcoin Trust, which converted into an ETF, has seen about $1.7 billion in volume, according to data compiled by Bloomberg. Meantime, BlackRock’s iShares Bitcoin Trust—IBIT— has seen over $880 million change hands. 

“This is definitely ground-breaking,” said Athanasios Psarofagis, an ETF analyst at Bloomberg Intelligence. “There was no doubt demand would be strong for these ETFs, but the numbers across the board are impressive.”

Still, it’s hard to compare Thursday’s activity to any other day in ETF history. Typically, only one fund that tracks a new asset class begins trading on a single day. It’s unprecedented to see over 10 nearly identical funds all begin at once. But even singling in on one ETF indicates the sheer magnitude of trading.

In just three hours, the Grayscale Bitcoin Trust has propelled itself to the third-most heavily traded ETF debut on record. To be sure, the product has existed in its trust structure since 2013, and had a nearly $27 billion headstart in asset size. 

Trading volume doesn’t indicate buying or selling or investor inflows. Because of the way the funds settle trades, net flows into or out of the products probably won’t be known until at least Friday.

When the initial Bitcoin futures fund began trading in 2021, it saw turnover of almost $1 billion during the entire first day. At the time, the futures fund debut was the second-most heavily traded fund on record. 

Psarofagis added a caveat that much of the demand may be from so called “seed” money that is pre-arranged by the fund issuers. Signs of more organic demand, like from retail investors or financial advisors, may come later on as more broker-dealers list the funds on their platforms.