Can someone make it trading only altcoins?
It depends on basically three factors, first of all are you able to get profits from the markets in a consistent way even when they are going down? For 90% of the traders the answer to this is no, and the next questions are what it is the rate of growth of your capital? And what is the size of your capital compare to your expenses? If you need to obtain 100% profits each year to sustain your lifestyle then forget about it, you are never going to make that amount of money and even if you do it for a few years you will take too much risks in the process and lose everything, in my opinion the maximum rate of growth you could get away with is 30%, I know these numbers may seem low to some people as the market of altcoins can move very abruptly but it is naive to think you can always win in this market.