Fixed exchange ratio
You know ownership but not value per share. You want to increase SP during NP - where is has the most influence. So u can give the same amount of money with less stocks
Floating exchange ratio
Determine price at end transaction period. So have to increase SP before. Value per stock is decided but not the ownership.
Passive media management
Increase SP due to good performance. Has to be persistent over time periods
Opportunistic acquisition
Takeover when stock of target is favourable. Not causality= if stock is up. Then MC is up