If I would had 10 thousand dollars, I would invest in bitcoin, because with such a sum you can invest in bitcoin and even need it to invest only in bitcoin with big amount. I might also have thought about investing in tether or stellar.
It is obvious that investing in bitcoin all of that money is not a bad choice but it is the most obvious one that you can make in this market and if you really want to multiply the amount of profits that you want to get then it is better to invest in altcoins that you know that can give you great profits but that are secure enough to hold for the long term.
if I had 10000$ I will put the other half to my investment coin then the other put to my saving, then if my investment grow the profit that I get from it will go to my saving then invest again to it. But if I saw a other have potential coin to invest then I will invest to it using my saving but not all of if just a little amount, so that the risk may take is lower.