Depends on how much I would need the $10k afterwards
I mean, if I can take a bit of risk, then I would put it in BURST. That thing has been just going up for the last two years - and still has lots'a room to multiply in value.
It's a bit risky though. So if I would have to safe-bet, then I would go with BTC.
I don't really see the point of ETH. It's neither safe nor does it have much upside left. Nor can it scale well.
To expand a bit: If ETH could rise 4-fold, then it would already be higher than BTC. Which is an ridiculous proposition. It has yet even to offer any use beyond programmers playing around. It wouldn't even be able to handle BTC's amount of transactions without running into size issues.
BURST and all the coins around there in the area can rise 20-fold and still wouldn't even be in the top 10. So even splitting between a bunch of promising ones to mitigate the risk would give more potential earnings.