Investing in the top 100 cryptocurrencies in the market can be one of the lowest risks that can be taken.
Not necessarily. Pumps can get coins to top 100, coins that are not backed by strong projects and they'll probably fail.
Even with projects considered strong, the risk is there - just look how bad were the last 4 months for Ethereum, even compared to Bitcoin.
Personally I invested that were not in the top 100 cryptocurrencies because they have more potential to profit. Still needs to choose very well.
High risk and high profit, of course. And yes, "Still needs to choose very well". It's not easy to find projects that will really have a future.
As a rule, before investing money, I study a project, if I see that this project is promising and there are high chances of a price increase, I invest in this project, even if it is not in the top 100.
This is the way. This and some degree of diversifying can do great things. A bit of luck is also needed.