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?
This problem is fixing itself. Bitcoin isn't that well distributed, but it's becoming more and more distributed over time. As the price rises, whales distribute to much smaller holders.
When I first started trading this market, it was normal to see whales buy/sell thousands of coins multiple times a day, pushing the market around. Today, we see this activity much less. Why? Because it may be easy for whales to dump thousands of coins, but it's often very difficult for whales to re-accumulate those coins. The fact that we're still trading at $4,000 10 years later and after a brutal bear market shows that demand for BTC is quite robust.
So while whales might be able to marginally push price around near the spread, their actions are always eventually absorbed by the market. And over time, there are less and less whales who can affect price like this.