Which one? Blackrock's "IBIT" ETF says $21M volume up until now: https://finance.yahoo.com/quote/IBIT/
Discussion
The combined trading volume of ALL ETFs
this is from earlier today and we now have gone past 2B
"All of the 11 ETFs have begun trading, and already over $1.4 billion has changed hands in just the first 45 minutes of trading. The Grayscale Bitcoin Trust has seen $634 million change hands, according to data compiled by Bloomberg. When the first Bitcoin futures fund began trading, it saw turnover of almost $1 billion during the entire day. At the time, the futures fund debut was the second-most heavily traded fund on record."
https://finance.yahoo.com/news/bitcoin-surges-past-49-000-145845991.html