Forex trading has no guaranteed profits, thus, everyone must not use a borrowed money just to invest with this type of invesment due to the unpredictable market. This type of market has a little return of investment, if you want to invest then be wise. Do not put all your money in one broker. Diversify your account.
The profit is not guaranteed on the Forex market, everything lies in uncertanties that's why experts discourage not to use borrowed funds. Moreover, the return of investmest is likely minimal due to the unprendictable movement & pne could lost his/her deposits in a little mistake.
Why should we trade using the money that is not ours in the first place? Forex trading is very risky and only a few succeeded from this kind of investment. If you wish to trade but you do not have money, then I advise you to participate to any of the contests of your broker. I'm sure most of the Forex brokers gives opportunities to the traders who cannot afford to invest by giving bonuses.