Chapter 13 Delta Hedging Flashcards
What is Delta Hedging?
It is buying an offsetting number of stocks (delta of an option) so that we don’t lose much as that option changes value
During Delta Hedging what 3 things can change the value of our “portfolio”, hint not GREEK
- Borrowing Capacity Change due of portfolio
- purchase or sale of new stock
- Interest payments
what is theta’s effect on delta hedging?
as time goes on, the value of an option decreases as theta decreases so works on market makers side
what is gamma’s effect on delta hedging?
Position becomes unhedged, so we lose money on large movements.
What is a self-financing portfolio
A portfolio that moves by one standard deviation, so that the market maker always breaks even.
The binomial model comes close to this, very close.
What is the formula for delta gamma change in option price approximation, using epsilon as the change in price
average delta is ((delta1 + delta1(epsilongamma))/2)
new Call price =
old Call price + epsilon * average delta
What is the formula for delta gamma and theta change in option price approximation, using epsilon as the change in price and h as change in time
average delta is ((delta1 + delta1(epsilongamma))/2)
new Call price =
old Call price + epsilon * average delta + h*theta
mean return on Delta Hedged position is
risk free rate
By rehedging more often (hourly vs. daily) you gain what in delta hedging
lower variance, specifically 1/24 for the daily vs. hourly.
Can you delta hedge for an american option tat should be exercised
no
Black Scholes partial differential equation is on 396
yep
What are 4 ways Market makers can avoid large payments when stocks make large moves
- buy deep out of money options
- variance swaps (make payement on low hcange , get payment on high change)
- create interest in offsetting options
- gamma neutral position
How to gamma hedge.
Find option and take raio of gammas to get how many of one to buy in relation of other, then fidn new delta and buy stocks(0 gamma) to ofset delta
Greeks for a binomial model
Gamma->
Delta of step up - delta of step down / (up stock price - down stock price) doesn’t work at time 0
Greeks for a binomial model
Theta->
use epsilon = uds - s and use delta gamma theta approximation.