> For the complete documentation index, see [llms.txt](https://eako-capital.gitbook.io/eako-user-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://eako-capital.gitbook.io/eako-user-guide/variations-on-barrier-options/knock-out-european-knock-out.md).

# Knock-Out European Knock-Out

A Knock-Out European Knock Out is a European option that ceases to exist (is "knocked-out") if the underlying spot breaches a predetermined barrier at any time before expiry.

The European Knock-Out barrier is valid at maturity only.