This is based on personal observation and studies of the altcoin market of a period of 2017/22
Altcoins are said to be the alternative cryptocurrency aside from Bitcoin and many of the altcoins are decentralized and also centralized, unlike Bitcoin which is highly decentralized and out of the control of anyone be it the developer or government Bitcoin has a total circulating supply. But Altcoin is developed by individuals e.g Vitalik Buterin Ethereum developer and teams members who are known in the society and the source codes of the coin can easily be updated which have made them not to have a static circulating which is has been the major reason why the altcoin market is hard to speculate because it circulating supply can easily be tempered more coin being minted at will which will render speculators analysis inaccurate in most cases.
That is not really the reason, the main reason for this has to do with technical analysis, most of the people in the market are using technical analysis to try to guess what will happen in the market next, however one of the known problems of technical analysis is that it does not work in an asset that has too small of a volume, and what is the man characteristic among most new coins in the market? That they have a low volume, so it is impossible to use technical analysis to try to infer their next movements.