If we have less new investors, so the prices tend to fluctuate less? How much dependent of new investors the prices are ?
It doesn't matter whether new or old investors as long as demand increases due to any reason prices will move up. Like last year media every day talk about cryptos good then it can attract many new small investors which also can increase demand for a particular coin to increase the price.
We need a lot of new investors, and especially small ones because that will give a more natural growth of the market.
We can talk of decentralization even when we talk of the value of a coin. When there are more people who hold the coin than there is a smaller chance that one holder or a group of holders to manipulate the market.
Yes, if more and more people hold the coin then market manipulation will reduce but still, they can try to manipulate by spreading fear in a new investor. These new investors are new to the highly volatile market so once it falls more than 10% in a day so many small investors will sell in a panic.