I don't believe they will simply cut the strike price in half. I believe they will allocate the strike price pro rata between their relative valuations. For example, today the "when issued" shares of ABBV closed at $34.32. Meanwhile ABT closed at $65.55. Thus, the market is impliedly valuing the "new" ABT at about $31.23. If the split occured tomorrow morning, I believe the value of your options would be roughly 34/31 as a ratio of value between ABBV/ABT. Does that make sense?