As we've already stated, trading on margin is trading on money borrowed from your broker. Each time you open a trade on margin, your broker automatically allocates the required margin from your existing funds in the trading account in order to back the margin trade. The precise amount of allocated funds depends on the leverage ratio used on your account.

Borrowing money to purchase securities is known as "buying on margin". When an investor borrows money from his broker to buy a stock, he must open a margin account with his broker, sign a related agreement and abide by the broker's margin requirements. The loan in the account is collateralized by investor's securities and cash. If the value of the stock drops too much, the investor must deposit more cash in his account, or sell a portion of the stock.

If traders are positive on the prospects for the Yen, they would expect the number on the right to go down – i.e. the Yen would be getting stronger against the Dollar. Traders would be buying less Yen with a Dollar as the Yen got stronger. Similarly, if the Yen was expected to weaken, forex traders would expect the Yen number to go up, reflecting the fact that the dollar could buy more yen.

We use real-time margining to allow you to see your trading risk at any moment of the day. Our real-time margin system applies margin requirements throughout the day to new trades and trades already on the books and enforces initial margin requirements at the end of the day, with real-time liquidation of positions instead of delayed margin calls. This system allows us to maintain our low commissions because we do not have to spread the cost of credit losses to customers in the form of higher costs.
If it was this easy to earn money utilising robots, nobody would ever go to work. It is possible that robots can make money for a restricted time period, but they could start losing after awhile - and the money earned by the 'best Forex robot' with one position may disappear before you can claim it. In addition, the vast majority of robots are scalpers. They make just a few pips with every position they take - and they can set a considerably tight target. The chances of surviving with such a strategy are quite limited for a trader.
GAIN Capital recommends you to seek independent financial and legal advice before making any financial investment decision. Trading CFDs and FX on margin carries a higher level of risk, and may not be suitable for all investors. The possibility exists that you could lose more than your initial investment further CFD investors do not own or have any rights to the underlying assets. 
Open positions are required to be fully margined at all times. does not engage in margin calls; you are responsible for monitoring your account and maintaining 100% of required margin at all times to support your open positions. To help limit your trading losses and ensure that your losses never exceed your account balance, our systems monitor your margin in near real-time and will automatically close out your open positions if your account equity falls below the 100% margin requirement. While our 100% margin requirement and near real-time margin system is designed to limit your trading losses and help ensure that total losses never exceed your total account balance, you do risk incurring losses greater than your account balance, especially during periods of extreme market volatility. While it is not’s policy to hold clients responsible for modest negative balances, we do reserve the right to hold clients responsible for large debit balances and when special circumstances apply. For this reason, we strongly encourage you to manage your use of leverage carefully. Increasing leverage increases risk.
Trading on margin is extremely popular among retail Forex traders. It allows you to open a much larger position than your initial trading account would otherwise allow, by allocating only a small portion of your trading account as the margin, or collateral for the trade. Trading on margin also carries certain risks, as both your profits and losses are magnified.
Forex margin is a good faith deposit that a trader puts up as collateral to initiate a trade. Essentially, it is the minimum amount that a trader needs in the trading account to open a new position. This is usually communicated as a percentage of the notional value (trade size) of the forex trade. The difference between the deposit and the full value of the trade is “borrowed” from the broker.
In particular I would like to make the system a lot faster, since it will allow parameter searches to be carried out in a reasonable time. While Python is a great tool, it's one drawback is that it is relatively slow when compared to C/C++. Hence I will be carrying out a lot of profiling to try and improve the execution speed of both the backtest and the performance calculations.