From GBTC's SEC filing
"Genesis”— Genesis Global Trading, Inc., a wholly owned subsidiary of Digital Currency Group, Inc., which as of the date of this Quarterly Report, is the only acting Liquidity Provider"
Liquidity Provider means they dump their bitcoins via them. Grayscale never buys and likely never will in the future due to the negative discount on their shares. They would only buy bitcoin if there was a premium. https://ycharts.com/companies/GBTC/discount_or_premium_to_nav
They sell BTC everyday to cover their 2% expense ratio. Total bitcoins they own is 633,601 BTC and 2% of that is 12,672 BTC. So they sell 12,672 BTC per year. That equals 35 BTC per day
So this means 35 less BTC being sold daily. Title is wrong i did math after. correct number is 35