Charm（Delta 时间衰减）

中文解释

Charm 描述的是时间流逝本身如何改变期权 Delta。它在临近到期时尤其重要，因为即使标的价格变化不大，时间衰减也可能快速改变做市商需要对冲的方向和规模。在 0DTE 市场里，Charm 可以帮助解释为什么盘中某些水位的重要性会随时间变化。

English definition

Charm is the rate at which an option delta changes as time passes. It matters most near expiration, where time decay can quickly alter dealer hedge demand even if spot is not moving much. In 0DTE markets, charm can help explain why hedging pressure changes through the day and why some price levels become more or less important as expiration approaches.

在 Nightwatch 里怎么看

Nightwatch 目前没有单独的 Charm 视图。收录这个词条，是因为它有助于理解临近到期时，为什么即使价格不动，做市商的对冲需求也会随时间推移而变化，这在 0DTE 盘中尤其明显。

Nightwatch does not currently provide a dedicated Charm view. The term is included because it helps explain why dealer hedging needs can shift with time alone as expiration approaches, especially in 0DTE sessions.