Developers are devloping coins that have use case nowadays so the growth of altcoins is not all dependant on the growth of bitcoin like before so altcoins are in serious green now

When i started crypto newly i invested 80 percent of my money and when it paid off i removed my profit and now i only input about 20 percent capital now and am enjoying the outcome

It depends on the project. If the project has a good team i prefer holding for a very long time because there is potential of it rising