Hi Jagankris,
You just mentioned in the last para that if you use speculation then it (trading) becomes gambling and if you use a pure strategy, MM, discipline then it becomes trading.
So the question if not how much money you put to trade, by use of MM, discipline. It is what you do when you decide to buy a stock to trade, it is speculation, you are speculating that the price ill go up. There is no science or art or mathematics involved, it is a mix of all including your gut feeling it is a plain speculation. You may try to name it Techincal or fundamental or price action or volume action or what ever just to distance yourself from gamblers but ultimately the decision to buy is nothing but speculating. Hence all traders are speculators, MM, discipline will only tell how long a trader will be in the market.
Thanks.