There is no right or wrong answer. If the deal were to fall through, then you'll lose. I guess it would depend on how many calls you bought. If it were me and I bought 10 calls, I would take profit on the majority of them, and let a few ride. That way, you lock in the majority of the profit, and let a few ride if the merger is approved, and still get some upside, and not lose all of your profits if something were go to wrong.