Not all altcoin you can invest. You should choose the altcoin with the price fluctuation of the day with great changes. As I think you should choose altcoin like bitcoin, eth or altcoin in the top 100 on coinmarkepcap for you to invest.
Why is everyone trying to invest in large altcoins? Look for investments among those Altcoins who can make good X's in the future, for example x10 or x100. Bitcoin can never make such x's. I choose projects and invest in them, one of these projects that can bring you a good profit is the project Etheera. I already bought tokens of this project and within a few weeks I already have a tangible income.