It means:
The opening price of the futures contract is 2648 points.
This price has been changing, changing with the change of spot index. In other words, the highest price of the Shanghai and Shenzhen 300 Index was around 2748.6, which was very close to the futures contract price (2748.6).
The difference between the futures price and the spot price (index) is called the basis. This base will fluctuate, but it will remain within a small range.
You got it? In other words, futures contracts have their own prices, which are constantly changing, and they also have their own trading rules. The buying and selling power of the market affects its price, but it is restricted by the spot price. (Because if the two deviate greatly, there will be arbitrage, and the power of arbitrage will not make the difference between the two great. )
(2748.6-2648)*300=30 180 yuan
Where 300 refers to the unit price of each index in the contract. Because it is a bull, the contract price increase means profit, so 2748.6 MINUS 2648 is the profit point, multiplied by 300 is the profitable money.
Margin 10%:
In other words, for the investment of 1000 yuan, I only need to pay 10000 yuan. Understand? So 2648*300 is the money you should spend to buy these points, and since the deposit is 10%, you only need to spend110, so multiply it by 10%.
Daily rate of return:
The money earned plus the money invested is the rate of return.