On July 5th, the copper smelter closed its position 100 lot of copper, and made a profit (58000-51200) *100 = 680000 yuan (excluding transaction fees).

In the spot market, the spot transaction was completed with the spot buyer at a price of 24,700 yuan. Assuming that the transaction volume is 200 tons, compared with March, the income is reduced by (28,000-24,700) * 200 = 660,000 yuan, and the actual income is 24,700 * 200 = 4.94 million yuan.

The smelter made a positive profit of 20,000 yuan in this basis hedging transaction.

I am also a beginner. It should be like this. When the hero sees something wrong, he hopes to point it out in time so as not to delay others' study! thank you