[yread]

isn't that how options work? selling something you don't own..

[regularfry]

Not really. But it can be how futures work.

[coolgeek]

It is in fact how naked puts work

http://en.wikipedia.org/wiki/Naked_put

[eru]

Aren't you talking about naked calls (http://en.wikipedia.org/wiki/Naked_call)?

[coolgeek]

Them too. Both involve "selling something you don't own" (the underlying security), a point disputed in the post I was replying to.

[eru]

I don't see how writing naked puts involves selling. They involve buying, only.

[Snurre]

All buying involve the counterpart selling. How can you buy something that isn't sold?