Why does coins prices fluctuate so much and it is never been constant making predicting price much harder and much riskier and holding on to coins can be the best way right now.
why does it change prices constantly and never stagnant?
Because markets are thin, which means that current buy and sell prices fluctuate.
Also because most coins are measured against BTC and ETH, so even if a coin has no trading, if ETH falls vs $, then that coin stays the same against ETH, and so also falls vs $.
Also because crypto is highly speculative, every coin offers a future use-case, which differs from the traditional non-crypto markets in which companies often have tangible assets and existing finished products.