Greetings from Turkey, we have recently started offering Options on futures and I am having some hard time explaining to my clients why they should place margins for LONG options positions. They mainly trade OTC options and they only pay the premium while buying options. I have been told that this due to the fact that those are on futures and been directed to CME page but could not find anything related. Some clients also says that some broker like SAXO do not ask for margins. I really appreciate if someone enlightens me on that.