/// <summary>
/// override the <method>DipathByAntitheticMethod</method>.
/// For Black Scholes model, mu and sigma is constant, and only one random
/// variate is needed to generate the state for next point
/// </summary>
public double[][] DipathByAntitheticMethod(StochasticAssetPrice S, GaussianGenerator nrandom,
double totalTime, int timeSteps, bool visualizationFlag = false, Form1 form = null)
{
double[][] pricePath = new double[2][];
pricePath[0] = new double[timeSteps + 1];
pricePath[1] = new double[timeSteps + 1];
StochasticAssetPrice S2 = new StochasticAssetPrice(S);
double dt = totalTime / (double)timeSteps;
pricePath[0][0] = S.CurrentPrice;
pricePath[1][0] = S.CurrentPrice;
for (int i = 1; i <= timeSteps; i++)
{
double z = nrandom.NextGaussian();
double z2 = -z;
pricePath[0][i] = GetNextPrice(S, dt, z);
pricePath[1][i] = GetNextPrice(S2, dt, z2);
}
if (visualizationFlag & form != null)
{
double[] X = new double[timeSteps + 1];
for (int i = 0; i <= timeSteps; i++)
{
X[i] = i;
}
form.add(X, pricePath[0], "");
form.add(X, pricePath[1], "");
}
return(pricePath);
}
/// <summary>
/// Override the <method>GetNextPrice</method> based on Euler Scheme
/// The StochasticAssetPrice object is updated in this method
/// </summary>
/// <returns> a double type value for the price of next stage</returns>
public override double GetNextPrice(StochasticAssetPrice S, double dt, params double[] Z)
{
double nextPrice = S.CurrentPrice + S.Mu * S.CurrentPrice * dt
+ S.Sigma * S.CurrentPrice * Z[0] * Math.Sqrt(dt);
S.CurrentPrice = nextPrice;
return(nextPrice);
}
/// <summary>
/// Override the <method>GetNextPrice</method> based on Discretization Scheme
/// for log price and Ito's lemma
/// The StochasticAssetPrice object is updated in this method
/// </summary>
/// <returns> a double type value for the price of next stage</returns>
public override double GetNextPrice(StochasticAssetPrice S, double dt, params double[] Z)
{
double nextPrice = S.CurrentPrice * Math.Exp((S.Mu - 0.5 * Math.Pow(S.Sigma, 2.0)) * dt
+ S.Sigma * Z[0] * Math.Sqrt(dt));
S.CurrentPrice = nextPrice;
return(nextPrice);
}
static void Main(string[] args)
{
//input needed information from keyboard
Console.WriteLine("Input spot price of underlying asset:");
double spotPrice = Convert.ToDouble(Console.ReadLine());
int oType;
do
{
Console.WriteLine("Input European option type (0 for call, 1 for put):");
oType = Convert.ToInt32(Console.ReadLine());
}while (oType != 0 & oType != 1);
OptionType optionType = (oType == 0 ? OptionType.Call : OptionType.Put);
Console.WriteLine("Input option strike price:");
double strikePrice = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input time to maturity of this option:");
double timeToMaturity = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input drift parameter for brownian motion:");
double Mu = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input volatility parameter for brownian motion:");
double sigma = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input number of scenarios generated by MC simulation:");
int numOfScenarios = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Input number of time steps for Euler discretization:");
int timeSteps = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Input whether to use antithetic variance reduction technique " +
"(true for yes,false for no): ");
bool antithetic = Convert.ToBoolean(Console.ReadLine());
EuropeanOption Option = new EuropeanOption(timeToMaturity, strikePrice, optionType);
EulerSchemeForBSModel Euler = new EulerSchemeForBSModel();
StochasticAssetPrice Asset = new StochasticAssetPrice(Mu, sigma, spotPrice);
if (antithetic)
{
double[] s1 = Option.PricingByMCSim(Asset, Euler, numOfScenarios, timeSteps,
true);
Console.WriteLine("Option price estimated by Monte Carlo Simulation and " +
"antithetic variance reduction is:\n {0:#0.00} \n Standard error is:\n {1:#0.000} ",
s1[0], s1[1]);
}
else
{
double[] s2 = Option.PricingByMCSim(Asset, Euler, numOfScenarios, timeSteps, false);
Console.WriteLine("Option price estimated by Monte Carlo Simulation is:\n {0:#0.00} \n" +
"Standard error is:\n {1:#0.000} ", s2[0], s2[1]);
}
Console.ReadLine();
}
/// <summary>
/// override the <method>GeneratingRandomPricePath</method>.
/// For Black Scholes model, mu and sigma is constant, and only one random
/// variate is needed to generate the state for next point.
/// </summary>
public double[] GeneratingRandomPricePath(StochasticAssetPrice S, GaussianGenerator nrandom,
double totalTime, int timeSteps)
{
double[] pricePath = new double[timeSteps + 1];
double dt = totalTime / (double)timeSteps;
pricePath[0] = S.CurrentPrice;
for (int i = 1; i <= timeSteps; i++)
{
double z = nrandom.NextGaussian();
pricePath[i] = GetNextPrice(S, dt, z);
}
return(pricePath);
}
/// <summary>
/// override the <method>PricingByMCSim</method>
/// In each scenario, a price path is generated and the option value under
/// this scenario is only decided by the final price. So, we take the average
/// for the 'value at maturity' of all the simulated scenarios and
/// discounted as the approximation for the option value.
/// This method also outputs the standard error for the approximation.
/// </summary>
public override double[] PricingByMCSim(StochasticAssetPrice S, IDiscretizationScheme D, int numOfScenarios,
int timeSteps, bool antitheticFlag)
{
double[] Result = new double[2]; //record the approximated price and standard error
double[] Sample = new double[numOfScenarios]; //record value at maturity for each scenario
double sumValue = 0.0; //record cumulative sum of Sample array
GaussianGenerator nrand = new GaussianGenerator();
if (antitheticFlag)
{
//when antithetic variance reduction technique is used
for (int i = 0; i < numOfScenarios; i++)
{
StochasticAssetPrice S1 = new StochasticAssetPrice(S);
double[][] PricePath;
PricePath = D.DipathByAntitheticMethod(S1, nrand, T, timeSteps);
Sample[i] = (ValueAtMaturity(PricePath[0][timeSteps])
+ ValueAtMaturity(PricePath[1][timeSteps])) / 2.0;
sumValue += Sample[i];
}
}
else
{
//when antithetic variance reduction technique is not used
for (int i = 0; i < numOfScenarios; i++)
{
StochasticAssetPrice S1 = new StochasticAssetPrice(S);
double[] PricePath;
PricePath = D.GeneratingRandomPricePath(S1, nrand, T, timeSteps);
Sample[i] = ValueAtMaturity(PricePath[timeSteps]);
sumValue += Sample[i];
}
}
double disFactor = Math.Exp(-S.Mu * T); //discount factor to convert value at maturity to current
Result[0] = sumValue / (double)numOfScenarios * disFactor;
double totalVariance = 0.0;
for (int i = 0; i < numOfScenarios; i++)
{
totalVariance += Math.Pow(Sample[i] - Result[0], 2.0);
}
if (numOfScenarios > 1)
{
double std = Math.Sqrt(totalVariance / (numOfScenarios - 1));
Result[1] = std / Math.Sqrt(numOfScenarios) * disFactor;
}
return(Result);
}
/// <summary>
/// override the <method>DipathByAntitheticMethod</method>.
/// For Black Scholes model, mu and sigma is constant, and only one random
/// variate is needed to generate the state for next point
/// </summary>
public double[][] DipathByAntitheticMethod(StochasticAssetPrice S, GaussianGenerator nrandom,
double totalTime, int timeSteps)
{
double[][] pricePath = new double[2][];
pricePath[0] = new double[timeSteps + 1];
pricePath[1] = new double[timeSteps + 1];
StochasticAssetPrice S2 = new StochasticAssetPrice(S);
double dt = totalTime / (double)timeSteps;
pricePath[0][0] = S.CurrentPrice;
pricePath[1][0] = S.CurrentPrice;
for (int i = 1; i <= timeSteps; i++)
{
double z = nrandom.NextGaussian();
double z2 = -z;
pricePath[0][i] = GetNextPrice(S, dt, z);
pricePath[1][i] = GetNextPrice(S2, dt, z2);
}
return pricePath;
}
/// <summary>
/// override the <method>DipathByAntitheticMethod</method>.
/// For Black Scholes model, mu and sigma is constant, and only one random
/// variate is needed to generate the state for next point
/// </summary>
public double[][] DipathByAntitheticMethod(StochasticAssetPrice S, GaussianGenerator nrandom,
double totalTime, int timeSteps)
{
double[][] pricePath = new double[2][];
pricePath[0] = new double[timeSteps + 1];
pricePath[1] = new double[timeSteps + 1];
StochasticAssetPrice S2 = new StochasticAssetPrice(S);
double dt = totalTime / (double)timeSteps;
pricePath[0][0] = S.CurrentPrice;
pricePath[1][0] = S.CurrentPrice;
for (int i = 1; i <= timeSteps; i++)
{
double z = nrandom.NextGaussian();
double z2 = -z;
pricePath[0][i] = GetNextPrice(S, dt, z);
pricePath[1][i] = GetNextPrice(S2, dt, z2);
}
return(pricePath);
}
/// <summary>
/// override the <method>GeneratingRandomPricePath</method>.
/// For Black Scholes model, mu and sigma is constant, and only one random
/// variate is needed to generate the state for next point.
/// </summary>
public double[] GeneratingRandomPricePath(StochasticAssetPrice S, GaussianGenerator nrandom,
double totalTime, int timeSteps, bool visualizationFlag = false, Form1 form = null)
{
double[] pricePath = new double[timeSteps + 1];
double dt = totalTime / (double)timeSteps;
pricePath[0] = S.CurrentPrice;
for (int i = 1; i <= timeSteps; i++)
{
double z = nrandom.NextGaussian();
pricePath[i] = GetNextPrice(S, dt, z);
}
if (visualizationFlag & form != null)
{
double[] X = new double[timeSteps + 1];
for (int i = 0; i <= timeSteps; i++)
{
X[i] = i;
}
form.add(X, pricePath, "");
}
return(pricePath);
}
/// <summary>
/// This method gives the estimated the option value
/// and the estimation standard error using MC simulation
/// </summary>
/// <param name="S"> describes the Brownian motion rule of the underlying asset</param>
/// <param name="D"> chooses the discretization scheme </param>
/// <param name="numberOfScenarios">decides the number of random paths to be generated</param>
/// <param name="timeSteps"> decides the number of intervals for discretization scheme </param>
/// <param name="antitheticFlag"> chooses whether to use antithetic variance reduction techniques</param>
/// <param name="visualizationFlag"> chooses whether to generate
/// the asset price chart for MC simulation</param>
/// <param name="form"> defines the window to display the graph</param>
/// <returns> a 2 elements array. The first one gives the estimated option price,
/// the second gives the estimation error</returns>
public abstract double[] PricingByMCSim(StochasticAssetPrice S, IDiscretizationScheme D,
int numberOfScenarios, int timeSteps, bool antitheticFlag, bool visualizationFlag, Form1 form = null);
/// <summary>
/// Override the <method>GetNextPrice</method> based on Discretization Scheme
/// for log price and Ito's lemma
/// The StochasticAssetPrice object is updated in this method
/// </summary>
/// <returns> a double type value for the price of next stage</returns>
public override double GetNextPrice(StochasticAssetPrice S, double dt, params double[] Z)
{
double nextPrice = S.CurrentPrice * Math.Exp((S.Mu - 0.5 * Math.Pow(S.Sigma, 2.0)) * dt
+ S.Sigma * Z[0] * Math.Sqrt(dt));
S.CurrentPrice = nextPrice;
return nextPrice;
}
public abstract double GetNextPrice(StochasticAssetPrice S, double dt, params double[] Z);
/// Copy method
public StochasticAssetPrice(StochasticAssetPrice S)
{
this.Mu = S.Mu;
this.sigma = S.Sigma;
this.currentPrice = S.CurrentPrice;
}
/// <summary>
/// This method gives the estimated the option value
/// and the estimation standard error using MC simulation
/// </summary>
/// <param name="S"> describes the Brownian motion rule of the underlying asset</param>
/// <param name="D"> chooses the discretization scheme </param>
/// <param name="numberOfScenarios">decides the number of random paths to be generated</param>
/// <param name="timeSteps"> decides the number of intervals for discretization scheme </param>
/// <param name="antitheticFlag"> chooses whether to use antithetic variance reduction techniques</param>
/// <returns> a 2 elements array. The first one gives the estimated option price,
/// the second gives the estimation error</returns>
public abstract double[] PricingByMCSim(StochasticAssetPrice S, IDiscretizationScheme D,
int numberOfScenarios, int timeSteps, bool antitheticFlag);
/// <summary>
/// override the <method>DipathByAntitheticMethod</method>.
/// For Black Scholes model, mu and sigma is constant, and only one random
/// variate is needed to generate the state for next point
/// </summary>
public double[][] DipathByAntitheticMethod(StochasticAssetPrice S, GaussianGenerator nrandom,
double totalTime, int timeSteps, bool visualizationFlag = false, Form1 form = null)
{
double[][] pricePath = new double[2][];
pricePath[0] = new double[timeSteps + 1];
pricePath[1] = new double[timeSteps + 1];
StochasticAssetPrice S2 = new StochasticAssetPrice(S);
double dt = totalTime / (double)timeSteps;
pricePath[0][0] = S.CurrentPrice;
pricePath[1][0] = S.CurrentPrice;
for (int i = 1; i <= timeSteps; i++)
{
double z = nrandom.NextGaussian();
double z2 = -z;
pricePath[0][i] = GetNextPrice(S, dt, z);
pricePath[1][i] = GetNextPrice(S2, dt, z2);
}
if (visualizationFlag & form != null)
{
double[] X = new double[timeSteps + 1];
for (int i = 0; i <= timeSteps; i++)
{
X[i] = i;
}
form.add(X, pricePath[0], "");
form.add(X, pricePath[1], "");
}
return pricePath;
}
static void Main(string[] args)
{
//input needed information from keyboard
Console.WriteLine("Input spot price of underlying asset:");
double spotPrice = Convert.ToDouble(Console.ReadLine());
int oType;
do
{
Console.WriteLine("Input European option type (0 for call, 1 for put):");
oType = Convert.ToInt32(Console.ReadLine());
}
while (oType != 0 & oType != 1);
OptionType optionType = (oType == 0 ? OptionType.Call : OptionType.Put);
Console.WriteLine("Input option strike price:");
double strikePrice = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input time to maturity of this option:");
double timeToMaturity = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input drift parameter for brownian motion:");
double Mu = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input volatility parameter for brownian motion:");
double sigma = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input number of scenarios generated by MC simulation:");
int numOfScenarios = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Input number of time steps for Euler discretization:");
int timeSteps = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Input whether to use antithetic variance reduction technique " +
"(true for yes,false for no): ");
bool antithetic = Convert.ToBoolean(Console.ReadLine());
Console.WriteLine("Input whether to visualize price path (true for yes,false for no): ");
bool visualizationFlag = Convert.ToBoolean(Console.ReadLine());
EuropeanOption Option = new EuropeanOption(timeToMaturity, strikePrice, optionType);
EulerSchemeForBSModel Euler = new EulerSchemeForBSModel();
StochasticAssetPrice Asset = new StochasticAssetPrice(Mu, sigma, spotPrice);
if (antithetic)
{
Form1 s1form = new Form1("MC Simulation with Antithetic Variance Reduction");
double[] s1 = Option.PricingByMCSim(Asset, Euler, numOfScenarios, timeSteps,
true, visualizationFlag, s1form);
Console.WriteLine("Option price estimated by Monte Carlo Simulation and " +
"antithetic variance reduction is:\n {0:#0.00} \n Standard error is:\n {1:#0.000} ",
s1[0], s1[1]);
if (visualizationFlag)
{
// display the graph
Application.Run(s1form.Display());
}
}
else
{
Form1 s2form = new Form1("MC Simulation without Antithetic Variance Reduction");
double[] s2 = Option.PricingByMCSim(Asset, Euler, numOfScenarios, timeSteps, false,
visualizationFlag, s2form);
Console.WriteLine("Option price estimated by Monte Carlo Simulation is:\n {0:#0.00} \n" +
"Standard error is:\n {1:#0.000} ", s2[0], s2[1]);
if (visualizationFlag)
{
// display the graph
Application.Run(s2form.Display());
}
}
Console.ReadLine();
}
/// <summary>
/// override the <method>GeneratingRandomPricePath</method>.
/// For Black Scholes model, mu and sigma is constant, and only one random
/// variate is needed to generate the state for next point.
/// </summary>
public double[] GeneratingRandomPricePath(StochasticAssetPrice S, GaussianGenerator nrandom,
double totalTime, int timeSteps)
{
double[] pricePath = new double[timeSteps + 1];
double dt = totalTime / (double)timeSteps;
pricePath[0] = S.CurrentPrice;
for (int i = 1; i <= timeSteps; i++)
{
double z = nrandom.NextGaussian();
pricePath[i] = GetNextPrice(S, dt, z);
}
return pricePath;
}
static void Main(string[] args)
{
//input needed information from keyboard
Console.WriteLine("Input spot price of underlying asset:");
double spotPrice = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input option strike price:");
double strikePrice = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input time to maturity of this option:");
double timeToMaturity = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input drift parameter for brownian motion:");
double Mu = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input volatility parameter for brownian motion:");
double sigma = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input number of scenarios generated by MC simulation:");
int numOfScenarios = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Input number of time steps for Euler discretization:");
int timeSteps = Convert.ToInt32(Console.ReadLine());
Console.WriteLine("Input whether to use antithetic variance reduction technique " +
"(true for yes,false for no): ");
bool antithetic = Convert.ToBoolean(Console.ReadLine());
EuropeanCallOption Option = new EuropeanCallOption(timeToMaturity, strikePrice);
EulerSchemeForBSModel Euler = new EulerSchemeForBSModel();
StochasticAssetPrice Asset = new StochasticAssetPrice(Mu, sigma, spotPrice);
if (antithetic)
{
double[] s1 = Option.PricingByMCSim(Asset, Euler, numOfScenarios, timeSteps,
true);
Console.WriteLine("Option price estimated by Monte Carlo Simulation and " +
"antithetic variance reduction is:\n {0:#0.00} \n Standard error is:\n {1:#0.000} ",
s1[0], s1[1]);
}
else
{
double[] s2 = Option.PricingByMCSim(Asset, Euler, numOfScenarios, timeSteps, false);
Console.WriteLine("Option price estimated by Monte Carlo Simulation is:\n {0:#0.00} \n" +
"Standard error is:\n {1:#0.000} ", s2[0], s2[1]);
}
Console.ReadLine();
}
/// <summary>
/// override the <method>PricingByMCSim</method>
/// In each scenario, a price path is generated and the option value under
/// this scenario is only decided by the final price. So, we take the average
/// for the 'value at maturity' of all the simulated scenarios and
/// discounted as the approximation for the option value.
/// This method also outputs the standard error for the approximation.
/// </summary>
public override double[] PricingByMCSim(StochasticAssetPrice S, IDiscretizationScheme D, int numOfScenarios,
int timeSteps, bool antitheticFlag, bool visualizationFlag = false, Form1 form = null)
{
double[] Result = new double[2]; //record the approximated price and standard error
double[] Sample = new double[numOfScenarios]; //record value at maturity for each scenario
double sumValue = 0.0; //record cumulative sum of Sample array
GaussianGenerator nrand = new GaussianGenerator();
if (antitheticFlag)
{
//when antithetic variance reduction technique is used
for (int i = 0; i < numOfScenarios; i++)
{
StochasticAssetPrice S1 = new StochasticAssetPrice(S);
double[][] PricePath;
PricePath = D.DipathByAntitheticMethod(S1, nrand, T, timeSteps, visualizationFlag, form);
Sample[i] = (ValueAtMaturity(PricePath[0][timeSteps])
+ ValueAtMaturity(PricePath[1][timeSteps])) / 2.0;
sumValue += Sample[i];
}
}
else
{
//when antithetic variance reduction technique is not used
for (int i = 0; i < numOfScenarios; i++)
{
StochasticAssetPrice S1 = new StochasticAssetPrice(S);
double[] PricePath;
PricePath = D.GeneratingRandomPricePath(S1, nrand, T, timeSteps, visualizationFlag, form);
Sample[i] = ValueAtMaturity(PricePath[timeSteps]);
sumValue += Sample[i];
}
}
double disFactor = Math.Exp(-S.Mu * T); //discount factor to convert value at maturity to current
Result[0] = sumValue / (double)numOfScenarios * disFactor;
double totalVariance = 0.0;
for (int i = 0; i < numOfScenarios; i++)
{
totalVariance += Math.Pow(Sample[i] - Result[0], 2.0);
}
if (numOfScenarios > 1)
{
double std = Math.Sqrt(totalVariance / (numOfScenarios - 1));
Result[1] = std / Math.Sqrt(numOfScenarios) * disFactor;
}
return Result;
}
static void Main(string[] args)
{
//input needed information from keyboard
Console.WriteLine("Input spot price of underlying asset:");
double spotPrice = Convert.ToDouble(Console.ReadLine());
while (spotPrice < 0)
{
Console.WriteLine("price must be positive, re-enter valide price:");
spotPrice = Convert.ToDouble(Console.ReadLine());
}
int oType;
do
{
Console.WriteLine("Input European option type (0 for call, 1 for put):");
oType = Convert.ToInt32(Console.ReadLine());
}while (oType != 0 & oType != 1);
OptionType optionType = (oType == 0 ? OptionType.Call : OptionType.Put);
Console.WriteLine("Input option strike price:");
double strikePrice = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input time to maturity of this option:");
double timeToMaturity = Convert.ToDouble(Console.ReadLine());
while (timeToMaturity < 0)
{
Console.WriteLine("time to maturity must be non-negative, re-enter valide value:");
timeToMaturity = Convert.ToDouble(Console.ReadLine());
}
Console.WriteLine("Input drift parameter for brownian motion:");
double Mu = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input volatility parameter for brownian motion:");
double sigma = Convert.ToDouble(Console.ReadLine());
while (sigma < 0)
{
Console.WriteLine("volatility parameter must be non-negative, re-enter valide value:");
sigma = Convert.ToDouble(Console.ReadLine());
}
Console.WriteLine("Input number of scenarios generated by MC simulation:");
int numOfScenarios = Convert.ToInt32(Console.ReadLine());
while (numOfScenarios < 1)
{
Console.WriteLine("this number must be positive, re-enter valide value:");
numOfScenarios = Convert.ToInt32(Console.ReadLine());
}
Console.WriteLine("Input number of time steps for discretization:");
int timeSteps = Convert.ToInt32(Console.ReadLine());
while (timeSteps < 1)
{
Console.WriteLine("this number must be positive, re-enter valide value:");
timeSteps = Convert.ToInt32(Console.ReadLine());
}
Console.WriteLine("Input whether to use antithetic variance reduction technique " +
"(true for yes,false for no): ");
bool antithetic = Convert.ToBoolean(Console.ReadLine());
Console.WriteLine("Input whether to visualize price path (true for yes,false for no): ");
bool visualizationFlag = Convert.ToBoolean(Console.ReadLine());
int discretizationScheme;
do
{
Console.WriteLine("Input discretization scheme (0 for Euler, 1 for Milstein, 2 for log price scheme):");
discretizationScheme = Convert.ToInt32(Console.ReadLine());
}while (discretizationScheme < 0 | discretizationScheme > 2);
EuropeanOption Option = new EuropeanOption(timeToMaturity, strikePrice, optionType);
IDiscretizationScheme scheme;
if (discretizationScheme == 0)
{
scheme = (IDiscretizationScheme)(new EulerSchemeForBSModel());
}
else if (discretizationScheme == 1)
{
scheme = (IDiscretizationScheme)(new MilsteinSchemeForBSModel());
}
else
{
scheme = (IDiscretizationScheme)(new LogPriceSchemeForBSModel());
}
StochasticAssetPrice Asset = new StochasticAssetPrice(Mu, sigma, spotPrice);
Form1 s1form = new Form1("MC Simulation");
double[] s1 = Option.PricingByMCSim(Asset, scheme, numOfScenarios, timeSteps,
antithetic, visualizationFlag, s1form);
if (antithetic)
{
Console.WriteLine("Option price estimated by Monte Carlo Simulation and " +
"antithetic variance reduction is:\n {0:#0.00} \n Standard error is:\n {1:#0.000} ",
s1[0], s1[1]);
}
else
{
Console.WriteLine("Option price estimated by Monte Carlo Simulation is:\n {0:#0.00} \n" +
"Standard error is:\n {1:#0.000} ", s1[0], s1[1]);
}
if (visualizationFlag)
{
// display the graph
Application.Run(s1form.Display());
}
Console.ReadLine();
}
public abstract double GetNextPrice(StochasticAssetPrice S, double dt, params double[] Z);
/// <summary>
/// override the <method>GeneratingRandomPricePath</method>.
/// For Black Scholes model, mu and sigma is constant, and only one random
/// variate is needed to generate the state for next point.
/// </summary>
public double[] GeneratingRandomPricePath(StochasticAssetPrice S, GaussianGenerator nrandom,
double totalTime, int timeSteps, bool visualizationFlag = false, Form1 form = null)
{
double[] pricePath = new double[timeSteps + 1];
double dt = totalTime / (double)timeSteps;
pricePath[0] = S.CurrentPrice;
for (int i = 1; i <= timeSteps; i++)
{
double z = nrandom.NextGaussian();
pricePath[i] = GetNextPrice(S, dt, z);
}
if (visualizationFlag & form != null)
{
double[] X = new double[timeSteps + 1];
for (int i = 0; i <= timeSteps; i++)
{
X[i] = i;
}
form.add(X, pricePath, "");
}
return pricePath;
}
static void Main(string[] args)
{
//input needed information from keyboard
Console.WriteLine("Input spot price of underlying asset:");
double spotPrice = Convert.ToDouble(Console.ReadLine());
while (spotPrice < 0)
{
Console.WriteLine("price must be positive, re-enter valide price:");
spotPrice = Convert.ToDouble(Console.ReadLine());
}
int oType;
do
{
Console.WriteLine("Input European option type (0 for call, 1 for put):");
oType = Convert.ToInt32(Console.ReadLine());
}
while (oType != 0 & oType != 1);
OptionType optionType = (oType == 0 ? OptionType.Call : OptionType.Put);
Console.WriteLine("Input option strike price:");
double strikePrice = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input time to maturity of this option:");
double timeToMaturity = Convert.ToDouble(Console.ReadLine());
while (timeToMaturity < 0)
{
Console.WriteLine("time to maturity must be non-negative, re-enter valide value:");
timeToMaturity = Convert.ToDouble(Console.ReadLine());
}
Console.WriteLine("Input drift parameter for brownian motion:");
double Mu = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Input volatility parameter for brownian motion:");
double sigma = Convert.ToDouble(Console.ReadLine());
while (sigma < 0)
{
Console.WriteLine("volatility parameter must be non-negative, re-enter valide value:");
sigma = Convert.ToDouble(Console.ReadLine());
}
Console.WriteLine("Input number of scenarios generated by MC simulation:");
int numOfScenarios = Convert.ToInt32(Console.ReadLine());
while (numOfScenarios < 1)
{
Console.WriteLine("this number must be positive, re-enter valide value:");
numOfScenarios = Convert.ToInt32(Console.ReadLine());
}
Console.WriteLine("Input number of time steps for discretization:");
int timeSteps = Convert.ToInt32(Console.ReadLine());
while (timeSteps < 1)
{
Console.WriteLine("this number must be positive, re-enter valide value:");
timeSteps = Convert.ToInt32(Console.ReadLine());
}
Console.WriteLine("Input whether to use antithetic variance reduction technique " +
"(true for yes,false for no): ");
bool antithetic = Convert.ToBoolean(Console.ReadLine());
Console.WriteLine("Input whether to visualize price path (true for yes,false for no): ");
bool visualizationFlag = Convert.ToBoolean(Console.ReadLine());
int discretizationScheme;
do
{
Console.WriteLine("Input discretization scheme (0 for Euler, 1 for Milstein, 2 for log price scheme):");
discretizationScheme = Convert.ToInt32(Console.ReadLine());
}
while (discretizationScheme < 0 | discretizationScheme > 2);
EuropeanOption Option = new EuropeanOption(timeToMaturity, strikePrice, optionType);
IDiscretizationScheme scheme;
if (discretizationScheme == 0)
{ scheme = (IDiscretizationScheme)(new EulerSchemeForBSModel()); }
else if (discretizationScheme == 1)
{ scheme = (IDiscretizationScheme)(new MilsteinSchemeForBSModel()); }
else
{ scheme = (IDiscretizationScheme)(new LogPriceSchemeForBSModel()); }
StochasticAssetPrice Asset = new StochasticAssetPrice(Mu, sigma, spotPrice);
Form1 s1form = new Form1("MC Simulation");
double[] s1 = Option.PricingByMCSim(Asset, scheme, numOfScenarios, timeSteps,
antithetic, visualizationFlag, s1form);
if (antithetic)
{
Console.WriteLine("Option price estimated by Monte Carlo Simulation and " +
"antithetic variance reduction is:\n {0:#0.00} \n Standard error is:\n {1:#0.000} ",
s1[0], s1[1]);
}
else
{
Console.WriteLine("Option price estimated by Monte Carlo Simulation is:\n {0:#0.00} \n" +
"Standard error is:\n {1:#0.000} ", s1[0], s1[1]);
}
if (visualizationFlag)
{
// display the graph
Application.Run(s1form.Display());
}
Console.ReadLine();
}
/// <summary>
/// Override the <method>GetNextPrice</method> based on Euler Scheme
/// The StochasticAssetPrice object is updated in this method
/// </summary>
/// <returns> a double type value for the price of next stage</returns>
public override double GetNextPrice(StochasticAssetPrice S, double dt, params double[] Z)
{
double nextPrice = S.CurrentPrice +S.Mu*S.CurrentPrice*dt
+S.Sigma*S.CurrentPrice*Z[0] * Math.Sqrt(dt);
S.CurrentPrice = nextPrice;
return nextPrice;
}
/// Copy method
public StochasticAssetPrice(StochasticAssetPrice S)
{
this.Mu = S.Mu;
this.sigma = S.Sigma;
this.currentPrice = S.CurrentPrice;
}
