It is impossible for the traders to have fixed income with bitcoin trading because the volatility or the movement of the price of bitcoin is not constant so it is not that easy for the traders to make profit with the same amount everyday because they need to analyze the market and find some good entry in the market to make profits but it is not that fixed income.
Correct, it's a hard job and if a person really understand trading he will be happy being profitable and not have fixed income
as he can maximize his income if he can be very consistent in predicting the price movement, there are times he will lose but he seek for improvement
so he'll succeed in the long run.