Economist lynde hull explained that the benefits of capital in different periods of time would be interest. According to linde hull, interest in a specific period and the difference between the expected consumption is savings (during the period of the growth of capital), and returns the sum of consumption and savings are given period of time. Edwards and bell's point of view According to the local biggest news agency Press Trust of India news agency (Press Trust of India) reported that, according to official sources in nine exchange about 2 million registered users, about 400000 to 500000 people have been conducting currency trade and investment. 2. Accounting earnings are based on the assumption of accounting instalments, which refers to the production and operation results of a certain period of time. Early accounting earnings is calculated according to the cash basis, and the modern accounting earnings is according to the classification current income and expenses of accrual basis, after the appropriate ratio calculated. However, the benefits of cash determination are more acceptable to users.