Do not invest in one basket because it is very risky. so invest in BNB and ETH so that you can benefit from both, there are many other altcoins that have potential and you also invest in some
Check out all the crypto funds that are legit and famous,,, the all lost money in 2018 and 2019. Guess why? Because they had it in a basket of crypto, that included things like ETH and BNB. If you really want to invest in crypto just do it for Bitcoin. everything else is a big, big risk,,, and more or less a gamble.
For the record. After bull run market, market correction and blood bath are expected to come to pass so it not about putting ones investment in one basket as you said but been inform and knowledgeable about the trend the market will possess before hand and take the necessary precautions.