s30cbf computes the price of a binary or digital cash-or-nothing option, together with the Greeks or sensitivities, which are the partial derivatives of the option price with respect to certain of the other input parameters. This option pays a fixed amount,
, at expiration if the option is in-the-money (see
Section 2.4 in the S Chapter Introduction). For a strike price,
, underlying asset price,
, and time to expiry,
, the payoff is therefore
, if
for a call or
for a put. Nothing is paid out when this condition is not met.
The price of a call with volatility,
, risk-free interest rate,
, and annualised dividend yield,
, is
and for a put,
where
is the cumulative Normal distribution function,
and
- 1: – Character(1)Input
-
On entry: determines whether the option is a call or a put.
- A call; the holder has a right to buy.
- A put; the holder has a right to sell.
Constraint:
or .
- 2: – IntegerInput
-
On entry: the number of strike prices to be used.
Constraint:
.
- 3: – IntegerInput
-
On entry: the number of times to expiry to be used.
Constraint:
.
- 4: – Real (Kind=nag_wp) arrayInput
-
On entry: must contain
, the th strike price, for .
Constraint:
, where , the safe range parameter, for .
- 5: – Real (Kind=nag_wp)Input
-
On entry: , the price of the underlying asset.
Constraint:
, where , the safe range parameter.
- 6: – Real (Kind=nag_wp)Input
-
On entry: the amount, , to be paid at expiration if the option is in-the-money, i.e., if
when , or if when , for .
Constraint:
.
- 7: – Real (Kind=nag_wp) arrayInput
-
On entry: must contain
, the th time, in years, to expiry, for .
Constraint:
, where , the safe range parameter, for .
- 8: – Real (Kind=nag_wp)Input
-
On entry: , the volatility of the underlying asset. Note that a rate of 15% should be entered as .
Constraint:
.
- 9: – Real (Kind=nag_wp)Input
-
On entry: , the annual risk-free interest rate, continuously compounded. Note that a rate of 5% should be entered as .
Constraint:
.
- 10: – Real (Kind=nag_wp)Input
-
On entry: , the annual continuous yield rate. Note that a rate of 8% should be entered as .
Constraint:
.
- 11: – Real (Kind=nag_wp) arrayOutput
-
On exit: contains , the option price evaluated for the strike price at expiry for and .
- 12: – IntegerInput
-
On entry: the first dimension of the arrays
p,
delta,
gamma,
vega,
theta,
rho,
crho,
vanna,
charm,
speed,
colour,
zomma and
vomma as declared in the (sub)program from which
s30cbf is called.
Constraint:
.
- 13: – Real (Kind=nag_wp) arrayOutput
-
On exit: the leading
part of the array
delta contains the sensitivity,
, of the option price to change in the price of the underlying asset.
- 14: – Real (Kind=nag_wp) arrayOutput
-
On exit: the leading
part of the array
gamma contains the sensitivity,
, of
delta to change in the price of the underlying asset.
- 15: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the first-order Greek measuring the sensitivity of the option price to change in the volatility of the underlying asset, i.e., , for and .
- 16: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the first-order Greek measuring the sensitivity of the option price to change in time, i.e., , for and , where .
- 17: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the first-order Greek measuring the sensitivity of the option price to change in the annual risk-free interest rate, i.e., , for and .
- 18: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the first-order Greek measuring the sensitivity of the option price to change in the annual cost of carry rate, i.e., , for and , where .
- 19: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the second-order Greek measuring the sensitivity of the first-order Greek to change in the volatility of the asset price, i.e., , for and .
- 20: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the second-order Greek measuring the sensitivity of the first-order Greek to change in the time, i.e., , for and .
- 21: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the third-order Greek measuring the sensitivity of the second-order Greek to change in the price of the underlying asset, i.e., , for and .
- 22: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the third-order Greek measuring the sensitivity of the second-order Greek to change in the time, i.e., , for and .
- 23: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the third-order Greek measuring the sensitivity of the second-order Greek to change in the volatility of the underlying asset, i.e., , for and .
- 24: – Real (Kind=nag_wp) arrayOutput
-
On exit: , contains the second-order Greek measuring the sensitivity of the first-order Greek to change in the volatility of the underlying asset, i.e., , for and .
- 25: – IntegerInput/Output
-
On entry:
ifail must be set to
,
. If you are unfamiliar with this argument you should refer to
Section 3.4 in How to Use the NAG Library and its Documentation for details.
For environments where it might be inappropriate to halt program execution when an error is detected, the value
is recommended. If the output of error messages is undesirable, then the value
is recommended. Otherwise, if you are not familiar with this argument, the recommended value is
.
When the value is used it is essential to test the value of ifail on exit.
On exit:
unless the routine detects an error or a warning has been flagged (see
Section 6).
If on entry
or
, explanatory error messages are output on the current error message unit (as defined by
x04aaf).
The accuracy of the output is dependent on the accuracy of the cumulative Normal distribution function,
. This is evaluated using a rational Chebyshev expansion, chosen so that the maximum relative error in the expansion is of the order of the
machine precision (see
s15abf and
s15adf). An accuracy close to
machine precision can generally be expected.
Please consult the
X06 Chapter Introduction for information on how to control and interrogate the OpenMP environment used within this routine. Please also consult the
Users' Note for your implementation for any additional implementation-specific information.
None.
This example computes the price of a cash-or-nothing call with a time to expiry of years, a stock price of and a strike price of . The risk-free interest rate is per year, there is an annual dividend return of and the volatility is per year. If the option is in-the-money at expiration, i.e., if , the payoff is .