I suggest looking into Cardano, Cosmos and Chainlink, even though they're not top 10

Instead of just a few altcoins, the investment could be diversified among more coins. As he points out, he can allocate some of the investment to some of the top coins, while the remaining amount can be allocated to the more risky ones. Thus, it regulates risks and gains. While he does not miss the expected opportunities, ensures the risky ones.