When trading contracts is no physical transfer of the selected asset from one owner to another, profits provide the difference in the cost of a particular product in different units of time. Trader should provide only the amount of collateral (4-15% of the transaction) and wait for the right moment.
CFD trading the underlying asset is similar to the trade by the underlying assets, the difference being that the trader is spared from having to pay for the registrar, depository and other related stock trading services. The price of the contract is a derivative of the selected asset prices, the trader profits from the trade about the same, but the overhead is much smaller. In the case of trade contracts, the trader also burdened property rights related to the acquisition or sale of assets.