衍生产品合约可私下达成，其市场缺乏规范，且没有公开交易信息的中心场所。

Derivatives transactions are struck privately and the market is unregulated, with no central exchange where trades are disclosed.

youdao

一度有消息说合同已经私下达成，我可不愿意去想世界上最好的球员之一可以随意出走，不尊重他的合同。

"Somewhere common sense and contracts have prevailed," he said. "You would not like to think that one of the biggest players in the world can just walk out and does not respect his contract."

youdao

It's illegal, so they can't sign that as a contract, but they they can just agree to do it.

因为是违法的,合同也就无效了,不过他们可以私下达成默契

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