That's usually the case with most brokers and more so with IB.Well now you see why I said getting a correct answer out of IB was next to impossible.
Owning one Jan '10 90 call gives you the right to buy 100 shares of GSF at $90 or $9,000. You cost basis will be $100 (strike plus cost of the call).I still can't get me head around how the $26/ share dividend plays into it. If I buy a Jan 09 90 GSF call now for $1000, they sure are not going to pay me $2600.
Based on the info that you provided, upon the completion of the merger, 100 shares of GSF will equal 50 shares of RIG plus $2,600 (which means there's some merger premium in GSF shares). Your Jan '10 90 call will give you the right to buy 50 chares of RIG and receive $2,600 for $9,000. IOW, you'll be paying $7,400 for 50 shares of RIG ($64 + $10)
All of this assumes that it's a simple adjustment by the OCC. If they adjust the strike or change any other terms, it's a different story.
And don't let the $7,400 throw you. It's an OTM call so obviously the cost basis will be higher than current prices. You concern is that both rise in the next 2+ years. And if it does, you don't have to exercise. You simple sell it to close.