If you have a lot of capital then I suggest go for bitcoin since its considered as the most volatile currency. It will surely be up again back to 16-17K. But if your low on budget then go for ADA,ETH,XRP.
"Low on budge" - he doesn't need to buy whole bitcoin..... he can buy parts of it
Nobody knows answer to your question, I will be happy if I knew and I'd pick the best one out there :/