Altcoins are always risky. But it depends on you have you manage them while purchasing them or Trading them. You have to go ahead with measuring risk of losses. And yeah, i also saw such pump dump theory in exchange. These are good for trade if you can manage. And in my opinion altcoins are still lower then their original value and it'll be increased once the bull session start dominating market. So right now, it could be opportunity to enter crypto makret and purchase your favorite altcoins or trade them if need
the volatility definitely higher than that of bitcoin, even ethereum is rather volatile though not as bad, if we see the new altcoins its always a roller coaster, right now the price is $1 tomorrow it can be $0.5 thats already half capital lost if you invest spot trading in that certain coin imagine you try to invest with leverage of 25x your money already gone long before it has 50% dump.
its overall a wild west with altcoin investment, whoever can manage to tolerate the risk they can make profit but they can go broke too, i'd expect anyone trying to invest in altcoin to know that before hand though.
but overall investing in altcoin isn't that risky where you can lost your money instantly though as long as you can try to make proper analysis and only find out the legitimate altcoin project.
investing when a coin first get listed on binance for example, usually the volatility can be taken advantage of to create massive profit just within short amount of time.