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NAG Toolbox: nag_specfun_opt_binary_con_price (s30ca)
Purpose
nag_specfun_opt_binary_con_price (s30ca) computes the price of a binary or digital cash-or-nothing option.
Syntax
[
p,
ifail] = s30ca(
calput,
x,
s,
k,
t,
sigma,
r,
q, 'm',
m, 'n',
n)
[
p,
ifail] = nag_specfun_opt_binary_con_price(
calput,
x,
s,
k,
t,
sigma,
r,
q, 'm',
m, 'n',
n)
Description
nag_specfun_opt_binary_con_price (s30ca) computes the price of a binary or digital cash-or-nothing option which pays a fixed amount,
, at expiration if the option is in-the-money (see
Option Pricing Routines 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
The option price is computed for each strike price in a set , , and for each expiry time in a set , .
References
Reiner E and Rubinstein M (1991) Unscrambling the binary code Risk 4
Parameters
Compulsory Input Parameters
- 1:
– string (length ≥ 1)
-
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:
– double array
-
must contain
, the th strike price, for .
Constraint:
, where , the safe range parameter, for .
- 3:
– double scalar
-
, the price of the underlying asset.
Constraint:
, where , the safe range parameter.
- 4:
– double scalar
-
The amount, , to be paid at expiration if the option is in-the-money, i.e., if
when , or if when , for .
Constraint:
.
- 5:
– double array
-
must contain
, the th time, in years, to expiry, for .
Constraint:
, where , the safe range parameter, for .
- 6:
– double scalar
-
, the volatility of the underlying asset. Note that a rate of 15% should be entered as 0.15.
Constraint:
.
- 7:
– double scalar
-
, the annual risk-free interest rate, continuously compounded. Note that a rate of 5% should be entered as 0.05.
Constraint:
.
- 8:
– double scalar
-
, the annual continuous yield rate. Note that a rate of 8% should be entered as 0.08.
Constraint:
.
Optional Input Parameters
- 1:
– int64int32nag_int scalar
-
Default:
the dimension of the array
x.
The number of strike prices to be used.
Constraint:
.
- 2:
– int64int32nag_int scalar
-
Default:
the dimension of the array
t.
The number of times to expiry to be used.
Constraint:
.
Output Parameters
- 1:
– double array
-
.
contains , the option price evaluated for the strike price at expiry for and .
- 2:
– int64int32nag_int scalar
unless the function detects an error (see
Error Indicators and Warnings).
Error Indicators and Warnings
Errors or warnings detected by the function:
-
-
On entry, was an illegal value.
-
-
Constraint: .
-
-
Constraint: .
-
-
Constraint: and .
-
-
Constraint: and .
-
-
Constraint: .
-
-
Constraint: .
-
-
Constraint: .
-
-
Constraint: .
-
-
Constraint: .
-
-
Constraint: .
-
An unexpected error has been triggered by this routine. Please
contact
NAG.
-
Your licence key may have expired or may not have been installed correctly.
-
Dynamic memory allocation failed.
Accuracy
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
nag_specfun_cdf_normal (s15ab) and
nag_specfun_erfc_real (s15ad)). An accuracy close to
machine precision can generally be expected.
Further Comments
None.
Example
This example computes the price of a cash-or-nothing put with a time to expiry of years, a stock price of and a strike price of . The risk-free interest rate is per year and the volatility is per year. If the option is in-the-money at expiration, i.e., if , the payoff is .
Open in the MATLAB editor:
s30ca_example
function s30ca_example
fprintf('s30ca example results\n\n');
put = 'P';
s = 100.0;
k = 10.0;
sigma = 0.35;
r = 0.06;
q = 0.0;
x = [80.0];
t = [0.75];
[p, ifail] = s30ca( ...
put, x, s, k, t, sigma, r, q);
fprintf('\nBinary (Digital): Cash-or-Nothing\n European Put :\n');
fprintf(' Spot = %9.4f\n', s);
fprintf(' Payout = %9.4f\n', k);
fprintf(' Volatility = %9.4f\n', sigma);
fprintf(' Rate = %9.4f\n', r);
fprintf(' Dividend = %9.4f\n\n', q);
fprintf(' Strike Expiry Option Price\n');
for i=1:1
for j=1:1
fprintf('%9.4f %9.4f %9.4f\n', x(i), t(j), p(i,j));
end
end
s30ca example results
Binary (Digital): Cash-or-Nothing
European Put :
Spot = 100.0000
Payout = 10.0000
Volatility = 0.3500
Rate = 0.0600
Dividend = 0.0000
Strike Expiry Option Price
80.0000 0.7500 2.2155
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