Method and system for modeling volatility
View Patent ↗A method for determining the implied volatility of a swap option employs intuitive factors to arrive at a close approximation of volatility. The volatility curve is a convex shaped curve which more closely follows real market volatility than previous methods. The slope of the curve is provided by employing a premium model which allows for a correlation between rates and volatility. The convex shaped curve is arrived by assuming a lognormal distribution for the underlying volatility.
1. A computer system for financial decisioning, the system generating a premium for an option, said option associated with a volatility, a volatility of volatility and a distribution type, said system comprising:
a computer processor programmed to:
receive a volatility distribution based on said volatility, said volatility of volatility, and said distribution type;
divide the volatility distribution into a plurality of portions, each said portion corresponding to a volatility, each said portion being associated with a probability;
determine an option premium for each volatility portion by employing a volatility premium calculation with rate r with forward value r , strike k, expiration time t, and annualized volatility σ according to the following formula:
BSQ
(
r
_
,
c
,
σ
,
t
)
=
r
_
1
q
·
Φ
(
d
1
)
+
r
_
(
1
-
1
q
-
k
~
)
·
Φ
(
d
2
)
Where Φ is the normal cumulative inverse function and
k
~
=
k
/
r
_
x
~
=
-
1
q
ln
[
(
k
~
-
1
)
q
+
1
]
/
(
σ
t
)
d
1
=
x
~
+
1
2
q
σ
t
d
2
=
x
~
-
1
2
q
σ
t
weigh each option premium by the probability associated with said volatility portion; and
sum all weighed premiums associated with said volatility portions to provide a premium for the option.
2. The system of claim 1 , wherein the processor is further programmed to perform an inverse Black procedure to determine the conventional market implied volatility for a strike rate that is different from the forward rate.
3. The system of claim 2 , wherein the processor is further programmed to compute the market price based on the conventional market implied volatility and comparing the generated premium to the market price.
4. The system of claim 3 , wherein the processor is further programmed to generate a decision to buy or sell the option based on the comparison.