All investment has it's risks, the best part to reduce risk investment is to choose on top alts in the market. Never invest if you don't know the project, as this is the main mistake of others. Invest in learning knowledge this will guide you throughout your journey in crypto.
Crypto itself is risky and for those who cannot take risk then it is not the right type of investment. Yes, not all altcoins are worth investing and only good handful projects will exist in future or whose value will continue to grow so selecting it and holding such coins are the key to make a good returns on your money.