I think the more coins and projects used for the intended purpose, the more stable the price for the alcoin itself, but the potential of the project is also very important, because the more potential the project looks good it will be the stronger the investor holds the coin in the portfolio (the investor can still buy coins ), Altcoin is always dynamic, because its market capitalization must be shared with other altcoins. But maybe a global coin like ethereum will be a little difficult to manipulate..