after tax profit Mehrotra said the additional rate for PC flash drives in 2017 is about 35 percent, and will increase to 75 percent by 2020. And "a lot of hard drives still need to be replaced by SSDS... Future self-driving vehicles are expected to be equipped with about 40GB of DRAM... This will also drive the use of NAND flash memory." Economic profits in perfect competition and monopolistic competition market has a special purpose, a positive profit can attract more enterprises to enter the market, increasing competition and push the market equilibrium price low, exclude some enterprises lack of competitiveness in the market, to achieve long-term equilibrium; On the contrary, negative economic profit can eliminate some of the original enterprises in the market, because the supply is reduced, the market equilibrium price will be pushed up, and the long-term equilibrium will be achieved. The result of the two cases is that economic profits disappear from each manufacturer and the manufacturer's total income is at the lowest point of average cost. It is not obvious in some analyses, but it is important to note that economic profits include opportunity costs. The profit of an entrepreneur (normal profit) is usually positive, but economic profit can be either positive or negative (loss). That's why the opportunity cost is included: in a completely competitive market, when marginal cost equals marginal revenue, profit maximization or loss minimization conditions arise. If the market price is lower than the total average cost, which means that the economic profit is negative, the entrepreneur needs to compare the value of the loss and the average variable cost. If the business continues to operate, the negative economic profit must not be lower than the average variable cost, otherwise the entrepreneur would rather shut down the company than continue to take the loss. Surplus value is created by employing workers in the process of direct production, but it must be transferred to the currency before it can be realized. Whether or not the goods can be sold and sold at what price, profits can be achieved and how much they can be achieved will depend on the specific conditions of supply and demand and market competition. In particular, capital goods of retrieval from the industry capital movement become the commercial capital, specific implementation of commodity value and surplus value function, and accordingly obtain business profits, make the relationship more complicated and more likely to cause mystification. In the process of circulation, some factors restricting the production process, or with, or to the conflict between capital and labor, into between capital and capital, pure relationship between buyers and sellers, and so on, all this will cover the production process with the difference between the circulation process, it is easier to put the cost price as the intrinsic value of the real goods, consider profit higher than the result of the sale of commodity value, the surplus value and commodity value contained in the implementation, in the process of circulation has been reversed expression is created from the sale. Because, the original business profits are exploited by industrial capital in the process of production to the part of the surplus value of transformation of form, but is considered in the process of circulation through the buy low sell high, produce, or paid by consumers upon. And class relations are distorted, business profits are reflect the commercial capitalist through industrial capitalists to hire laborers, the relationship between exploitation and exploitation were buried, and distortion of between capitalist and capitalist and capitalist with pure commodity trading relationship between the consumers. The standard variable interest rate (SVR) is usually adjusted at the base rate, and these standard variable interest rates (SVR) are not fixed or floating transactions. Stopping trading is an important part of the plan.