Bitcoin has a market cap of 70 billion. This is very low when compared with the stock market or the gold market. There are many groups that can buy the total number of Bitcoin in circulation with a price of $4000. They can easily manipulate the market both sides up or down. Bitcoin 70% supply is stored in a very less number of wallets say 5%. Don't you think Bitcoin can easily manipulate and below $1000 is still possible?
First of all, I don't see the correlation between bitcoin being manipulated and prices having to go below $1k.
In every market, there is a certain degree of centralisation, and manipulation. It's a matter of what that degree is exactly.
I personally think that the significance of "whales" that somehow manipulate the entire market due to their large holdings is really largely a myth, and narratives of bitcoin's volatility being caused by manipulation per se is most likely unbacked as well.
That said, though, the small market cap in relation to other asset classes does mean that smaller orders will be able to move the market more. Though, when you look at the potential manipulation through derivatives in other markets like precious metals, I don't think bitcoin is easy to manipulate, though it might be easy for a large investor to move the market.