Certainly, once you are a consistently profitable trader (if that ever happens) it would make sense to plough money into your account in order to grow it.
Not necessarily.
Certainly, once you are a consistently profitable trader (if that ever happens) it would make sense to plough money into your account in order to grow it.
%%Not necessarily.

Investments dont have a comission problem ;

Not necessarily.
I have been trading as an amateur for around 7 or 8 years, and in that time have done reasonably well some of the time, but have gradually lost money overall, probably around £2000 over that time, which from some of the stories on here, doesn't seem too bad.
I have never funded my account with more than £1000. Currently it is around £300 and has been for some time. I trade every day to learn how to do it better.
Time and again I see the advice not to trade unless you have a large account (£10000 + seems common).
Given that most traders, and presumably nearly all new traders, lose money, to have a large account when you start would seem to be very foolhardy.
While you will never make much money with a small account, there are enough online brokers out there who will let you invest for very small stakes while you learn how to trade competently.
My day job is trading secondhand books, which started on a shoestring but now makes a healthy income. I regularly spend thousands of pounds on buying books, because I know what I am doing. However, when I started out, it was daunting to spend £100 on a book, and I made many mistakes.
It seems to me to be the same with trading stocks/indices/forex or whatever. Until you know what you are doing, it is madness to trade in large amounts. If you ever get any good at it, use your profits to increase your trading size, and eventually you will have a large account to trade. Am I missing something here?
In some cases, you can reduce your risk by having more capital.
For example, trading a long/short stock position in related names. You can lever the difference of two related stocks. While requiring more capital, this may in fact have less risk on a gross exposure/notional basis. Buying an S&P sector, and selling a different sector (or basket of stocks) is an example.
You can also qualify for portfolio margin with a large account, which in some cases reduces liquidation risk, or opens the door to some interesting risk management strategies. Long/short, beta neutral, or relative value are examples.
Another option for smaller account sizes is diversification. By spreading your investments across different asset classes or sectorsHedging is the strategy most trusted by financial institutions and traders with bigger investment.