Buying altcoins these days is a good idea? I don't think so but I did earlier with small amount only because I am not satisfied with the situation of the market.
So for me, I just bought Ethereum. Why Ethereum? Because it is the highest market cap altcoin now and I believe that even if the market will still bleed in the coming days/weeks/months, I am hoping the dump is small percentage only compare to other altcoins.
We don't know where the crypto market will go: up or down. Therefore, if the prices of crypto currencies rise, then, theoretically, altcoins can bring good profits. As a rule, altcoins are more frisky in terms of growth compared to bitcoin, which has already gained its weight and is somewhat clumsy in terms of growth dynamics (it is not able to show even x10).
I also think Ethereum is a good choice, but I decided to take a chance and buy some BNB, because the upside seems to me higher. If we compare Ethereum and BNB, then BNB is cheaper, which means it can show more profit. The choice in favor of BNB is due to the fact that this is not a empty-coin that no one needs and is not used by anyone, but is in demand because of the fame of binance and has some use in the same exchange.