
31a99426b8662077eb28d88ce2f7a882.ppt
- Количество слайдов: 26
A New View of Mortgages (and life)
Scene 1 • A farmer owns a horse farm outside Lexington on Richmond Road. • Demographic trends indicate that this part of Lexington is booming and is projected to continue to grow. • Problem: Current local government is hostile to development.
Scene 2 • Local developer notices the horse farm and thinks that the site is an excellent candidate for a new shopping mall. • Developer knows that the local mayor is up for re-election next year. Outcome of election is uncertain, but has potential to install new mayor with pro-growth views.
Scene 3 • What can the developer do to take advantage of this opportunity? • Approach farmer with an offer to buy an option to purchase the horse farm.
The Option • Developer pays the farmer $X for the right to purchase the horse farm after the election for $Y. • If pro-growth mayor wins, then horse farm will be worth $Z 1 (where E[Z 1] > Y). – developer exercises the right to purchase the land for $Y and either develops the shopping mall or sells to another for $Z 1 (profit = Z 1 -Y).
The Option • If current mayor wins, horse farm will be worth $Z 2 where $Z 2 < $Y. – Can assume that Z 2 is probably the value of the land as a farm. – Developer lets option expire without purchasing land – Farmer keeps the payment $X.
Next Example • An insurance company has a large real estate portfolio. • The insurance company projects that it will need $1 million next year to fund possible claims. • What can it do to protect itself from changes in value to its real estate portfolio between now and when the claims will have to be paid.
Answer • Purchase an option to sell one of its properties for $1 million. • If prices go down then protected • If prices go up, will lose the appreciation but still locked in with enough funds to pay the claims.
Options • In the first example, the developer purchased a CALL option. – the right to buy an asset • In the second example, the insurance company purchased a PUT option. – the right to sell an asset.
Call Option • Contract giving its owner the right to purchase a fixed number of shares of a specified common stock at a fixed price by a certain date • • • Stock = underlying security (ST = market price) price = strike price (K) date = expiration date writer = person who issues the call (the seller) buyer = person who purchases the call price = market price of the call, (CT)
Types of Call Options • European Call = exercise only at maturity • American Call = exercise at any time up to maturity
Call Option Payoff at Maturity
Put Option • Contract giving its owner the right to sell a fixed number of shares of a specified stock at a fixed price at any time by a certain date.
Put Option Payoff at Maturity
Mortgages as Options • A mortgage is a promise to repay a debt secured by property. – property = collateral = underlying security = stock • However, a mortgage is much more complex than a simple stock option. – mortgage is a contract with several options
Mortgages as Options • Default Option – right of borrower to stop making payments in exchange for the property – default = exercise of a PUT option
Mortgages as Options • Prepayment Option – right of borrower to prepay the mortgage at any time – prepayment = exercise of a CALL option
Prepayment • Paying off mortgage early (prior to maturity date) – Financial = when interest rates fall below contract rate – Non-financial = borrower moves, divorce, (not optimal with respect to interest rates) – prepayment is considered to be an American option • borrower may prepay at any time prior to maturity
Default • Mortgage Default is defined as a failure to fulfill a contract – Technical default = breech of any provision of the mortgage contract • 1 day late on payment • failure to pay property taxes • failure to pay insurance premiums
Default • Industry Standards: – Delinquency: missed payment – Default = 90 days delinquent • (3 missed payments) – Foreclosure: process of selling the property to pay off the debt • takes many months to foreclosure
Default • Default is considered a European put option. – Borrowers will only default when a payment is due – Thus, the mortgage can be thought of as a string of default options. Every time you make a payment, you are purchasing a put option giving you the right to sell the house to the lender for the mortgage balance next month.
Default and Prepayment • Default and Prepayment are substitutes. – If borrower prepays the mortgage, then he can’t default • implies that default has no value – If borrower defaults on the mortgage, then she can’t prepay • implies that prepayment has no value
Mortgage Pricing • Ten years ago Enterprise S&L made a 30 year mortgage for $100, 000 at an annual interest rate of 8%. The current market rate for an equivalent loan is 12%. What is the market value of this loan?
Mortgage Pricing • Simplistic Answer: Price = $66, 640 • More Complex (realistic) – Price = PV of Payments - Value of Default Option - Value of Prepayment Option