if with a capital of 100 $ I think you better invest in etherium tokens because if there is enough to buy even though it's only 0.1 ETH and we'll see if it will go up to 2k $ then of course the profits will get bigger. Regarding bitcoin, I think it's lacking, but if you are willing to invest in the long term then it is not a problem because bitcoin every year makes a lot of people surprised by the price that is achieved.