Phenomenal strategies that have been proven by backtesting to be extremely prolific are often very delusive and the first reason why novice traders end up being disillusioned after the very first real trades. Before proceeding to calculus, you must understand that backtesting softwares as well as demo accounts that are meant to gauge the effectiveness of your strategy in most of the cases over appreciate its yield. Obviously, they have many reasons to do it. For example, if a rookie trader is willing to test his newly invented strategy and the potential outcome turns out to be extremely rewarding, it works as an encouragement and psychologically enhances his chances to pay for the professional version that he had tested. In reality, during the first few experiences traders often lose money or break it even, but this must be a lesson, not a sign to stop.
[B]Once you advance and have more experience under your belt, you can rely on a stable profit, but it still fluctuates. On a long run I would recommend you to have, a strong capital account as the more stocks you hold the higher the reward. Beware though of brokers that recommend margin trading as it usually leads a penniless trader from being flat broke to getting into huge debt. However, most of the traders are still officially unemployed so you must take into consideration the additional fees that you have to pay as a self-employed trader including medical assurance fees and other charges that every citizen is usually imposed through his employee.
Overall, after enough endeavors you can live entirely off trading. However, it requires a decent sum of money in order to have a strong initial capital for investments, pay for the broker or trading software and enough to ensure yourself a living at the beginning. Thus, I don't recommend you to make this switch suddenly, but after at least two or three years you can confidently make this lifechange and benefit of the advantages outlined like schedule flexibility and potentially high income.