I think 100 coins in investments are relatively safe compared to other altcoins. But we cannot deny their risk .You need to analyze the coin in which you want to invest.
I also think its less risky to purchase coins in the top 100 than to invest in ICOs or buy coins with a small cap. But does it matter? The cryptocurrency is much riskier than investments in estate or deposits anyway! In the cryptocurrency market, you have to think three times before taking a step!