if my advice is to have a capital of 600 dollars then I will invest in altcoins that have high potential such as ETH, NEO and LTC. because these three coins will benefit greatly if you make a long-term investment
I would also suggest investment in altcoin but $600 is not a big amount and I think it will enable you to own two ETH maximum or a singly Litecoin plus a fraction of ETH. Since the current market is depicted as an incentive to invest in any coin that is advanced in terms of technology and has low price as well. As the market recovers, your investment will also grow in worth and this is the ultimate return what an investor wants.
if you only have that much the best option is to invest in ethereum, which is currently still cheap, with $ 600 you will get 3 eth and hold until next year the profit will be met.