Opportunity cost Renting:
You currently pay $10,000 per year in a rent to a landlord for a $100,000 house, which you are considering purchasing. you can wualify for a loan of $80,000 at 9% if you put $20,000 down on the house. To raise money for your own downpayment, you would have to liquidate stock earning a 15% return. Neglect other concerns, like costing costs, capital gains, and tax consequences of owning, and determine whether it is better to rent or own.