Yes, it is possible to trading without using the indicator. I saw some traders who did not use any indicator while trading. Even if they did not ask someone trade expert once in the trade. They trade only by seeing the price rise and down chart. Even if they could tell any cryptocurrency they would increase in the future. They could say the future of any cryptocurrency. I think they and you are very skilled at trading.
Thank you
Both people who use indicator or not can be professional, because using indicator not means that people have no skill. But sometime out there who not use indicator only speculate in market and then buy and sell his coin according to price only.