thanks all for the reply, fyi, think some of the asian indices have quarterly futures contract with monthly options in the first 3 months, so I would be leaning towards adding the borrowing cost. I was referring to cash settled options on the actual index rather than options on the futures (index futures)hopefully I get enough market prices to verify. I was googling around just after posting the question and I found this article
http://www.risk.net/risk-magazine/news/ ... strategies about negative repos causing the Nikkei forwards to distort, guess either way, I'll need to put some borrow cost in there.thanks again.