Chapter 7 - Pricing of Options (Done) Flashcards
What is delta?
Indicates how much the price of an
option is expected to change, given a
price change in the underlying interest.
What is delta hedging?
Adjusting the number of contracts
used in an option hedge to reflect the
option’s delta.
What is historical volatility?
Past or historical volatility of an
underlying asset, measured by taking
the standard deviation of price changes
over a set period of time.
Historical volatility measures how much the price of a stock has fluctuated over a specific period in the past.
In short, historical volatility tells you how erratic the stock’s price has been over the chosen past period, regardless of the current price or time of year.
What is implied volatility?
The volatility implicit in an option’s
premium.
Implied volatility is a measure of the market’s expectation of how much the price of a stock will fluctuate in the future, as inferred from the option’s price.
So, implied volatility tells you how much the market thinks the stock’s price will move going forward.
Implied volatility is reflected in the price of the option.
What is intrinsic value?
For a call option, intrinsic value is
calculated by subtracting the exercise
price from the market price. For a put
option, intrinsic value is calculated by
subtracting the market price from the
exercise price. For both calls and puts,
intrinsic value cannot be less than zero.
What is time value?
The premium of the option less its
intrinsic value.
What is volatility?
A statistical measure of how much
a given security or market index
fluctuated during a given time period.
Describe the difference between intrinsic value and time value.
- Intrinsic value represents the real and tangible value of an option and is based solely on the relationship
between the option’s strike price and the price of the underlying asset. - Time value is the amount that an option is trading in excess of its intrinsic value. The time value of an option
depends on several factors, as noted below. As the level of uncertainty about where the underlying price will
be at expiration increases, the amount of time value built into an option’s premium increases.
List the factors that affect intrinsic value and time value
- Intrinsic Value
If an option is in-the-money, intrinsic value is the difference between the strike price and the underlying price.
Prior to expiration, all American-style options and virtually all European-style options trade at a price that is
at least equal to their intrinsic value.
Occasionally (although very rarely), a European-style option will trade at a “discount” to its intrinsic value.
The discount can be thought of as negative time value. The fact that a discount can arise is a direct result of
the two different exercise features. - Time Value
The time remaining to expiration has an important effect on the time value of an option. The longer an option
has until expiry, the more the option will be worth. However, the relationship between time and an option’s
value is not linear. An option’s time value decays faster the closer the option is to expiration.
In terms of dollars, the time value of an option is at its maximum when the underlying price is equal to the
strike price (i.e., the option is at-the-money). As the option moves in-the-money or out-of-the-money, the
dollar amount of time value decreases (although the percentage of an option’s premium represented by time
value may go up or down).
Perhaps the most important variable affecting time value is the expected volatility of the underlying asset. All
else being equal, the more volatile the market expects the underlying asset to be over the life of the option,
the more time value will be built into the option premium and the more the option will be worth. This is true
for both calls and puts. Historical volatility is the actual past volatility exhibited by the price of the underlying
asset. Traders will sometimes use historical volatility as an estimate of future volatility when using option-
pricing models. To understand what level of volatility the market is building into the price of an option, the
price of the option is fed into an option-pricing model, and the model is solved for volatility. The volatility
figure arrived at through this process is known as the option’s implied volatility.
The net cost of carrying the underlying asset is also a determinant of the amount of time value built into an
option’s premium. The cost of carrying most underlying assets consists of the risk-free rate of interest and any
yield on the underlying instrument.
Explain how changes in these factors affect an option’s value.
Holding all other variables the same, changes in the factors that affect an option’s value impact call and put
premiums as follows:
- An increase in the volatility of the underlying asset increases both call and put premiums. A decrease in the
volatility of the underlying asset decreases both call and put premiums.
- An increase in the risk-free interest rate increases call premiums and decreases put premiums. A decrease in
the risk-free interest rate decreases call premiums and increases put premiums.
- An increase in the yield of the underlying asset decreases call premiums and increases put premiums.
A decrease in the yield of the underlying asset increases call premiums and decreases put premiums.
Yield of the Underlying Asset
Impact:
An increase in the yield of the underlying asset decreases call premiums and increases put premiums. A decrease in the yield of the underlying asset increases call premiums and decreases put premiums.
Why:
Call Options: If the underlying asset pays a higher yield (e.g., dividends for stocks), holding the asset becomes more attractive compared to holding the option. This is because owning the actual asset allows the holder to receive the yield, whereas holding a call option does not. As a result, the premium for call options decreases. Put Options: Higher yields make holding the asset less attractive since the asset's price may drop after yielding a dividend or interest payment. This makes put options more valuable because there's a higher chance the asset's price will decrease, making it more likely the put will end up in-the-money.
Risk-Free Interest Rate
Impact:
An increase in the risk-free interest rate increases call premiums and decreases put premiums. A decrease in the risk-free interest rate decreases call premiums and increases put premiums.Call OptionsCost of Carry: Holding an asset requires funding. If you can invest money at a higher risk-free rate instead, the opportunity cost of holding the asset increases. Why: Higher risk-free rates mean higher returns on alternative investments (like bonds), which makes holding the underlying asset (and thus holding the call option to buy it later) more attractive.Put OptionsCost of Holding the Underlying Asset: If interest rates are higher, the opportunity cost of holding cash (rather than the underlying asset) increases. Why: Investors might prefer to hold cash or risk-free assets that earn a higher interest rate rather than holding the underlying asset, making put options (the right to sell the asset) less valuable.
Describe and explain the importance of an option’s delta
An option’s delta is a number that measures the approximate change in the value of an option premium given a
1-unit change in the price of the underlying asset.
Option deltas are important for a variety of reasons. First, option deltas allow option traders to estimate how
much an option value will change given a change in the price of the underlying asset. If an option trader has an
opinion on the price of the underlying asset, this can be used to estimate the return on an option position.
Second, an option’s delta acts like a hedge ratio, allowing hedgers to estimate the number of contracts required
to hedge a position in the underlying asset. To use the delta as a hedge ratio, divide the option-adjusted size
of the exposure being hedged by the option’s delta. The option-adjusted size of the exposure is the size of the
exposure divided by the option’s trading unit.
Because deltas change as the price of the underlying asset changes, a delta hedging program needs to be
constantly monitored for changes in option deltas.
Calculate an option’s delta given all the inputs.
The inputs required to calculate an option’s delta are the change in the price of the underlying asset and the
corresponding change in the price of the option.
Delta = Change in Price of the Option / Change in Price of the Underlying Asset
Calculate the expected change in an option’s price given the delta and the change in the underlying
asset’s price.
A simple rearrangement of the above formula provides the following formula for calculating the expected
change in an option’s price given the delta and the change in the underlying asset’s price:
Change in Price of an Option = Delta × Change in Price of the Underlying Asset
DEF 50 call options are trading at $5. DEF stock is trading at $56. If DEF options have an American-style
exercise feature, which of the following steps must be taken to exploit the arbitrage opportunity?
a. Buy DEF 50 call options at $5 and sell DEF stock short at $56.
b. Sell DEF 50 call options at $5 and buy DEF stock at $56.
c. Buy DEF 50 call options at $5, sell DEF stock short at $56 and exercise the options.
d. Sell DEF 50 call options at $5, buy DEF stock at $56 and exercise the options.
c. Buy DEF call options at $5, sell DEF stock short at $56 and exercise the options.
XYZ stock is trading at $40. Which of the following options (all expiring in the same year) will have the
greatest dollar amount of time value built into its price?
a. XYZ March 35 calls.
b. XYZ March 40 calls.
c. XYZ June 35 calls.
d. XYZ June 40 calls
d. XYZ June 40 calls.
All else being equal, at-the-money options have the greatest dollar amount of time value built into their
price. All else being equal, options with a longer time to expiration will have a higher premium than options
with a shorter time to expiration