Is there a general consensus on how much volume it takes to move the BTC market price?
I am happy that it is not me alone who knows that the cryptocurrency market is being manipulated. But the market capital of Bitcoin is discouraging it, yet it is happening as we can see during the ETF saga and some other few times that people may not even notice much. But there can't be a general consensus for this, once the money is big enough, it could possibly move the market as they want depending on the condition the big amount met the market with.
Why are you so sure that the market is being manipulated. Especially Bitcoin. Bitcoin is not promising smart contracts or a world computer. It is just the penultimate settlement layer and reserve currency of the evolving Web3/ DLT world.
Also, when it comes to market manipulation, it is generally stuff like insider trading that corporations can engage in, specifically the people within those organizations who are privy to privileged information. In case of Bitcoin, there is hardly anything that can be hidden. The network is transparent for everyone to see and anybody who tries to buy/ sell the news is going to do it in full public view.
Unless the SEC itself is compromised about the ETF news.