1/48
d<1+Rf<u
True
Delta
(Cu - Cd) / (Us - Ds)
Delta of a Call is between
0 and 1
Delta of a Put is between
-1 and 0
How do you hedge a portfolio using call options
Buy delta number of shares and short 1 call
Pi
(1 + rf - d) / (u - d)
The price of an option
(Pi Cu + (1-Pi) * Cd) / (1 + rf)
The price of an option with two periods
Square Pi and rf and add 2 * Pi to (1-PI)
Rate of return
(new value - old value) / old value
how do you hedge a portfolio using put options
short delta number of shares and buy 1 put
Time Value is always positive
Call Option
Time Value can be negative
Put Option
dividends encourage early exercise
call option
dividends discourage exercise
put option
why do dividends discourage the exercise of a put option
the stock price will decrease after a dividend is paid
To find the price of an option with dividends
(1 - dividend yield) * us (ds)
to find the price of an option with a fixed dividend
u*s - fixed dividend
What kind of model is the binomial pricing model
discrete
what kind of model is the black-scholes pricing model
continuous
the binomial model evenutally becomes the black-scholes model with enough periods
true
discrete return
normal rate of return
continuous return
log(1+discrete)
-1<x<infinity
discrete return
-infinity<x<inifinity
continuous return
the assumptions of the B-S model
stock return are log normally distributed
constant risk-free rate and constant volatility
no taxes and no transaction costs
no dividends
European option
How do you find the true usable values of d1 and d2
t-distribution chart
if the current stock price is very high
d1 and d2 are = infinity
is the current stock price is close to 0
d1 and d2 are = negative infinity
if the option expires in the money
d1 and d2 are = infinity
in the option expires at the money
d1 and d2 = negative infiniy
in the option expires out of the money
d1 and d2 = negative infinity
if the standard deviation is 0 and the current stock price is larger than the continuous return of the exercise price, OR the exercise price is = 0
d1 and d2 = infinity
if the standard deviation is 0 and the stock price is less than the continuous return of the exercise price
d1 and d2 = negative infinity
call option delta
(change in option price / change of stock price)
greater than 0
call option gamma
(change of delta / change of stock price)
greater than 0
call option Rho
(change in option price / change of interest rate)
greater than 0
call option vega
(change of option price / change in volatility)
greater than 0
what is the only unobservable variable
volatility
call option theta
(change in option price / change in time-to-maturity)
less than zero
which greek variable measures time-value decay
theta
what makes the B-S price equal to the market
implied volatility
as time to expiration increases, the implied volatility increases
true
volatility smile (skew)
implied volatility is low for at the money options and high for in the money and out of the money options
as implied volatility increases, the “expensiveness” of an option decreases
true
Put delta
-1 < x < 0
put gamma
greater than 0
put rho
less than 0
put vega
less than zero
put theta
greater than 0 OR less than 0