Have you thought about the flip side of it? When these big corporates are buying Bitcoin in bulk, the price is increasing. A lot of people sharing about it.
But what would happen if these corporates start selling their Bitcoins in bulk? The price will start dropping.
With 1.5 billion worth of holding, these corporates hold the power to manipulate crypto market. I hope no company start buying Bitcoin anymore!
That is a very good point. Further more, price increases slowly when bullish but drops significantly in a bearish trend.
So if we see the same amount of sell off then the price drop will be huge when compared to it's price pump.
In a way it is better that institutional investors stay away from bitcoin because if a single entity holds a large amount of bitcoins it will give them the power of market manipulation as you said.