1: Suppose this person has 10 yuan.

Spend 8 yuan to buy a chicken, and there are 2 yuan left in your hand.

2: 9 yuan sells, leaving 1 1 yuan.

I bought it at 3: 10, and I still have 1 left in my hand.

4: 1 1 Yuan has been sold again, and there is still 12 yuan in hand. (12- 10=2 yuan)

Extended data:

(1) The reasons for the price difference are complicated. For example, the geographical environment is different, the relationship between supply and demand is different, the labor price is different, and the culture is different. And mastering the law of price difference seems to be a necessary condition for businessmen to make profits.

(2) The spread will increase and decrease, but when the spread of two futures contracts is abnormal, it provides arbitrage opportunities for traders. The difference in price is related to profit. The real difficulty for arbitrageurs is how to capture the biggest difference in prices under the same trend.

References:

Baidu encyclopedia-price difference