Please clarify yourself

没有现货合约，可以卖空吗？

Of course you can. This is pure speculation.

Sometime the exchange may distinguish pure speculation and hedging. For example, pure speculation needs more initial and maintenance margin or there is some constraint on the maximum contract number a single account can open.

If you hold the spot asset, so what you do is something like hedging, in that case, it is less risky so that there is less limit. But in this case you need to provide some eligible document to show that you are a qualified hedging trader. For speculation trader, as long you open an account, you are one. You can open a futures contract whenever you like you don't need to have the spot asset.

best，

Thank you very much