If you had $500, which coins would you choose to buy
an altcoin that is not yet in the top 500, because it has the potential to make my $500 into $5k or even $50k, but of course the risk is definitely big (high risk, high profit) and altcoin that I recommend is UMB, because I see this project as a hidden gem, so when the right time comes, then the price will definitely increase very high, so of course UMB has a good potential to be used as a long-term investment and can make me rich, but if you want to invest in UMB, then I still advise you to DYOR before investing in UMB.
Never heard of it before and why do you think it is hidden gem? What makes this coin stands out vs the hundreds of other coins that are out there? I would divide the money and buy 5 coins to divide the risk a bit. Everyone got his own favorite coins but I am more a fan of "bigger" altcoins like ETH or BNB.