Gray investor are not the only one who contributed to the price of Bitcoin and why we are having a bull run, there are whales who are also doing this and there are also group whales that are selling their shares, investors small and big have different mindset and motivation at different times, because there's no group of big group that controls the market, we will have a big pump and a big dip if they unite and agreed to sell or buy.
Grayscale is one of those investors that helped. Let's not act as if they are the only reason I agree with that, but let's not act as if they had no role in it neither, we are talking about 500k+ purchased from the market and no longer in the market, buying and holding helps bitcoin price stay up and they did that in a massive massive scale.
Sure the price did increased aside from them as well, there must have been so much more people who bought and hold since then, maybe at least that much or even more, liquidity is getting lower and lower which shows that people buy bitcoin and hold it and not sell it, however we can't argue that grayscale wasn't a part of that neither. We are in a bull run for the past 1 year and we can say that we have done marvelous job at that as a whole, every single person who has bought bitcoin and hold it is part of this increase.