Before, because the spot dealer signed a contract to exchange goods, he had to pay.

There will be a series of default risks.

Futures are contracts with spot as the subject matter, and they are basically standardized except for price.

Futures trading is not about handing over the spot to the exchange.

For example, if you have a pen and I want to buy your pen, we will reach an agreement through the online store, pay a certain deposit, and then take the voucher to get the pen. If I need it at that time, you can put the pen in the designated store and I will get the goods. But if I just speculate, I can transfer that voucher transaction to someone else. This should be well understood. The exchange is equivalent to a platform, and the store is equivalent to a delivery warehouse.