[dharmatech]

Put options have an expiration. So I'm curious what you mean by "open-end"?

[Kranar]

Options exist with no expiration date, but they are not commonly traded. There's nothing in principle unusual about them, at least not more so than most other derivatives.

[turnsout]

Yeah, not a thing. You can short a stock long-term, but that's an easy way to become insolvent.

[Kranar]

Perpetual options are a thing, although not mainstream.