For the long term, of course investing in crypto which is currently top 20 is profitable and safe, but for the short term, investing in coins that are still cheap or below $ 0.5 is what will make our money skyrocket.
Yes, if you invest in top-20 cryptocurrencies, you will not lose at least: the altcoins from this list will not leave the market. meanwhile, sometimes, penny alts give more profits. Check it:
https://coinmarketcap.com/gainers-losers/