public void testDiscretizationError()
{
// Testing the discretization error of the Heston Hull-White process
DayCounter dc = new Actual360();
Date today = Date.Today;
Settings.Instance.setEvaluationDate(today);
// construct a strange yield curve to check drifts and discounting
// of the joint stochastic process
List <Date> dates = new List <Date>();
List <double> times = new List <double>();
List <double> rates = new List <double>(), divRates = new List <double>();
for (int i = 0; i <= 31; ++i)
{
dates.Add(today + new Period(i, TimeUnit.Years));
// FLOATING_POINT_EXCEPTION
rates.Add(0.04 + 0.0001 * Math.Exp(Math.Sin(i)));
divRates.Add(0.04 + 0.0001 * Math.Exp(Math.Sin(i)));
times.Add(dc.yearFraction(today, dates.Last()));
}
Date maturity = today + new Period(10, TimeUnit.Years);
double v = 0.25;
Handle <Quote> s0 = new Handle <Quote>(new SimpleQuote(100));
SimpleQuote vol = new SimpleQuote(v);
Handle <BlackVolTermStructure> volTS = new Handle <BlackVolTermStructure>(Utilities.flatVol(today, vol, dc));
Handle <YieldTermStructure> rTS = new Handle <YieldTermStructure>(new InterpolatedZeroCurve <Linear>(dates, rates, dc));
Handle <YieldTermStructure> qTS = new Handle <YieldTermStructure>(new InterpolatedZeroCurve <Linear>(dates, divRates, dc));
BlackScholesMertonProcess bsmProcess = new BlackScholesMertonProcess(s0, qTS, rTS, volTS);
HestonProcess hestonProcess = new HestonProcess(rTS, qTS, s0, v * v, 1, v * v, 1e-6, -0.4);
HullWhiteForwardProcess hwProcess = new HullWhiteForwardProcess(rTS, 0.01, 0.01);
hwProcess.setForwardMeasureTime(20.1472222222222222);
double tol = 0.05;
double[] corr = { -0.85, 0.5 };
double[] strike = { 50, 100, 125 };
for (int i = 0; i < corr.Length; ++i)
{
for (int j = 0; j < strike.Length; ++j)
{
StrikedTypePayoff payoff = new PlainVanillaPayoff(Option.Type.Put, strike[j]);
Exercise exercise = new EuropeanExercise(maturity);
VanillaOption optionBsmHW = new VanillaOption(payoff, exercise);
HullWhite hwModel = new HullWhite(rTS, hwProcess.a(), hwProcess.sigma());
optionBsmHW.setPricingEngine(new AnalyticBSMHullWhiteEngine(corr[i], bsmProcess, hwModel));
double expected = optionBsmHW.NPV();
VanillaOption optionHestonHW = new VanillaOption(payoff, exercise);
HybridHestonHullWhiteProcess jointProcess = new HybridHestonHullWhiteProcess(hestonProcess,
hwProcess, corr[i]);
optionHestonHW.setPricingEngine(
new MakeMCHestonHullWhiteEngine <PseudoRandom, Statistics>(jointProcess)
.withSteps(1)
.withAntitheticVariate()
.withAbsoluteTolerance(tol)
.withSeed(42).getAsPricingEngine());
double calculated = optionHestonHW.NPV();
double error = optionHestonHW.errorEstimate();
if ((Math.Abs(calculated - expected) > 3 * error &&
Math.Abs(calculated - expected) > 1e-5))
{
QAssert.Fail("Failed to reproduce discretization error"
+ "\n corr: " + corr[i]
+ "\n strike: " + strike[j]
+ "\n calculated: " + calculated
+ "\n error: " + error
+ "\n expected: " + expected);
}
}
}
}
public void testAnalyticHestonHullWhitePricing()
{
// Testing analytic Heston Hull-White option pricing
DayCounter dc = new Actual360();
Date today = Date.Today;
Settings.Instance.setEvaluationDate(today);
// construct a strange yield curve to check drifts and discounting
// of the joint stochastic process
List <Date> dates = new List <Date>();
List <double> times = new List <double>();
List <double> rates = new List <double>(), divRates = new List <double>();
for (int i = 0; i <= 40; ++i)
{
dates.Add(today + new Period(i, TimeUnit.Years));
// FLOATING_POINT_EXCEPTION
rates.Add(0.03 + 0.0001 * Math.Exp(Math.Sin(i / 4.0)));
divRates.Add(0.02 + 0.0002 * Math.Exp(Math.Sin(i / 3.0)));
times.Add(dc.yearFraction(today, dates.Last()));
}
Date maturity = today + new Period(5, TimeUnit.Years);
Handle <Quote> s0 = new Handle <Quote>(new SimpleQuote(100));
Handle <YieldTermStructure> rTS = new Handle <YieldTermStructure>(new InterpolatedZeroCurve <Linear>(dates, rates, dc));
Handle <YieldTermStructure> qTS = new Handle <YieldTermStructure>(new InterpolatedZeroCurve <Linear>(dates, divRates, dc));
HestonProcess hestonProcess = new HestonProcess(rTS, qTS, s0, 0.08, 1.5, 0.0625, 0.5, -0.8);
HestonModel hestonModel = new HestonModel(hestonProcess);
HullWhiteForwardProcess hwFwdProcess = new HullWhiteForwardProcess(rTS, 0.01, 0.01);
hwFwdProcess.setForwardMeasureTime(dc.yearFraction(today, maturity));
HullWhite hullWhiteModel = new HullWhite(rTS, hwFwdProcess.a(), hwFwdProcess.sigma());
double tol = 0.002;
double[] strike = { 80, 120 };
Option.Type[] types = { Option.Type.Put, Option.Type.Call };
for (int i = 0; i < types.Length; ++i)
{
for (int j = 0; j < strike.Length; ++j)
{
HybridHestonHullWhiteProcess jointProcess = new HybridHestonHullWhiteProcess(hestonProcess,
hwFwdProcess, 0.0, HybridHestonHullWhiteProcess.Discretization.Euler);
StrikedTypePayoff payoff = new PlainVanillaPayoff(types[i], strike[j]);
Exercise exercise = new EuropeanExercise(maturity);
VanillaOption optionHestonHW = new VanillaOption(payoff, exercise);
optionHestonHW.setPricingEngine(new MakeMCHestonHullWhiteEngine <PseudoRandom, Statistics>(jointProcess)
.withSteps(1)
.withAntitheticVariate()
.withControlVariate()
.withAbsoluteTolerance(tol)
.withSeed(42).getAsPricingEngine());
VanillaOption optionPureHeston = new VanillaOption(payoff, exercise);
optionPureHeston.setPricingEngine(new AnalyticHestonHullWhiteEngine(hestonModel, hullWhiteModel, 128));
double calculated = optionHestonHW.NPV();
double error = optionHestonHW.errorEstimate();
double expected = optionPureHeston.NPV();
if (Math.Abs(calculated - expected) > 3 * error &&
Math.Abs(calculated - expected) > tol)
{
QAssert.Fail("Failed to reproduce hw heston vanilla prices"
+ "\n strike: " + strike[j]
+ "\n calculated: " + calculated
+ "\n error: " + error
+ "\n expected: " + expected);
}
}
}
}
public void testCallableEquityPricing()
{
// Testing the pricing of a callable equity product
/*
* For the definition of the example product see
* Alexander Giese, On the Pricing of Auto-Callable Equity
* Structures in the Presence of Stochastic Volatility and
* Stochastic Interest Rates .
* http://workshop.mathfinance.de/2006/papers/giese/slides.pdf
*/
int maturity = 7;
DayCounter dc = new Actual365Fixed();
Date today = Date.Today;
Settings.Instance.setEvaluationDate(today);
Handle <Quote> spot = new Handle <Quote>(new SimpleQuote(100.0));
SimpleQuote qRate = new SimpleQuote(0.04);
Handle <YieldTermStructure> qTS = new Handle <YieldTermStructure>(Utilities.flatRate(today, qRate, dc));
SimpleQuote rRate = new SimpleQuote(0.04);
Handle <YieldTermStructure> rTS = new Handle <YieldTermStructure>(Utilities.flatRate(today, rRate, dc));
HestonProcess hestonProcess = new HestonProcess(rTS, qTS, spot, 0.0625, 1.0, 0.24 * 0.24, 1e-4, 0.0);
// FLOATING_POINT_EXCEPTION
HullWhiteForwardProcess hwProcess = new HullWhiteForwardProcess(rTS, 0.00883, 0.00526);
hwProcess.setForwardMeasureTime(dc.yearFraction(today, today + new Period(maturity + 1, TimeUnit.Years)));
HybridHestonHullWhiteProcess jointProcess = new HybridHestonHullWhiteProcess(hestonProcess, hwProcess, -0.4);
Schedule schedule = new Schedule(today, today + new Period(maturity, TimeUnit.Years), new Period(1, TimeUnit.Years),
new TARGET(), BusinessDayConvention.Following, BusinessDayConvention.Following, DateGeneration.Rule.Forward, false);
List <double> times = new InitializedList <double>(maturity + 1);
for (int i = 0; i <= maturity; ++i)
{
times[i] = i;
}
TimeGrid grid = new TimeGrid(times, times.Count);
List <double> redemption = new InitializedList <double>(maturity);
for (int i = 0; i < maturity; ++i)
{
redemption[i] = 1.07 + 0.03 * i;
}
ulong seed = 42;
IRNG rsg = (InverseCumulativeRsg <RandomSequenceGenerator <MersenneTwisterUniformRng>
, InverseCumulativeNormal>)
new PseudoRandom().make_sequence_generator(jointProcess.factors() * (grid.size() - 1), seed);
MultiPathGenerator <IRNG> generator = new MultiPathGenerator <IRNG>(jointProcess, grid, rsg, false);
GeneralStatistics stat = new GeneralStatistics();
double antitheticPayoff = 0;
int nrTrails = 40000;
for (int i = 0; i < nrTrails; ++i)
{
bool antithetic = (i % 2) != 0;
Sample <IPath> path = antithetic ? generator.antithetic() : generator.next();
MultiPath value = path.value as MultiPath;
Utils.QL_REQUIRE(value != null, () => "Invalid Path");
double payoff = 0;
for (int j = 1; j <= maturity; ++j)
{
if (value[0][j] > spot.link.value())
{
Vector states = new Vector(3);
for (int k = 0; k < 3; ++k)
{
states[k] = value[k][j];
}
payoff = redemption[j - 1] / jointProcess.numeraire(grid[j], states);
break;
}
else if (j == maturity)
{
Vector states = new Vector(3);
for (int k = 0; k < 3; ++k)
{
states[k] = value[k][j];
}
payoff = 1.0 / jointProcess.numeraire(grid[j], states);
}
}
if (antithetic)
{
stat.add(0.5 * (antitheticPayoff + payoff));
}
else
{
antitheticPayoff = payoff;
}
}
double expected = 0.938;
double calculated = stat.mean();
double error = stat.errorEstimate();
if (Math.Abs(expected - calculated) > 3 * error)
{
QAssert.Fail("Failed to reproduce auto-callable equity structure price"
+ "\n calculated: " + calculated
+ "\n error: " + error
+ "\n expected: " + expected);
}
}
public void testZeroBondPricing()
{
// Testing Monte-Carlo zero bond pricing
DayCounter dc = new Actual360();
Date today = Date.Today;
Settings.Instance.setEvaluationDate(today);
// construct a strange yield curve to check drifts and discounting
// of the joint stochastic process
List <Date> dates = new List <Date>();
List <double> times = new List <double>();
List <double> rates = new List <double>();
dates.Add(today);
rates.Add(0.02);
times.Add(0.0);
for (int i = 120; i < 240; ++i)
{
dates.Add(today + new Period(i, TimeUnit.Months));
rates.Add(0.02 + 0.0002 * Math.Exp(Math.Sin(i / 8.0)));
times.Add(dc.yearFraction(today, dates.Last()));
}
Date maturity = dates.Last() + new Period(10, TimeUnit.Years);
dates.Add(maturity);
rates.Add(0.04);
//times.Add(dc.yearFraction(today, dates.Last()));
Handle <Quote> s0 = new Handle <Quote>(new SimpleQuote(100));
Handle <YieldTermStructure> ts = new Handle <YieldTermStructure>(new InterpolatedZeroCurve <Linear>(dates, rates, dc));
Handle <YieldTermStructure> ds = new Handle <YieldTermStructure>(Utilities.flatRate(today, 0.0, dc));
HestonProcess hestonProcess = new HestonProcess(ts, ds, s0, 0.02, 1.0, 0.2, 0.5, -0.8);
HullWhiteForwardProcess hwProcess = new HullWhiteForwardProcess(ts, 0.05, 0.05);
hwProcess.setForwardMeasureTime(dc.yearFraction(today, maturity));
HullWhite hwModel = new HullWhite(ts, 0.05, 0.05);
HybridHestonHullWhiteProcess jointProcess = new HybridHestonHullWhiteProcess(hestonProcess, hwProcess, -0.4);
TimeGrid grid = new TimeGrid(times);
int factors = jointProcess.factors();
int steps = grid.size() - 1;
SobolBrownianBridgeRsg rsg = new SobolBrownianBridgeRsg(factors, steps);
MultiPathGenerator <SobolBrownianBridgeRsg> generator = new MultiPathGenerator <SobolBrownianBridgeRsg>(
jointProcess, grid, rsg, false);
int m = 90;
List <GeneralStatistics> zeroStat = new InitializedList <GeneralStatistics>(m);
List <GeneralStatistics> optionStat = new InitializedList <GeneralStatistics>(m);
int nrTrails = 8191;
int optionTenor = 24;
double strike = 0.5;
for (int i = 0; i < nrTrails; ++i)
{
Sample <IPath> path = generator.next();
MultiPath value = path.value as MultiPath;
Utils.QL_REQUIRE(value != null, () => "Invalid Path");
for (int j = 1; j < m; ++j)
{
double t = grid[j]; // zero end and option maturity
double T = grid[j + optionTenor]; // maturity of zero bond
// of option
Vector states = new Vector(3);
Vector optionStates = new Vector(3);
for (int k = 0; k < jointProcess.size(); ++k)
{
states[k] = value[k][j];
optionStates[k] = value[k][j + optionTenor];
}
double zeroBond
= 1.0 / jointProcess.numeraire(t, states);
double zeroOption = zeroBond * Math.Max(0.0, hwModel.discountBond(t, T, states[2]) - strike);
zeroStat[j].add(zeroBond);
optionStat[j].add(zeroOption);
}
}
for (int j = 1; j < m; ++j)
{
double t = grid[j];
double calculated = zeroStat[j].mean();
double expected = ts.link.discount(t);
if (Math.Abs(calculated - expected) > 0.03)
{
QAssert.Fail("Failed to reproduce expected zero bond prices"
+ "\n t: " + t
+ "\n calculated: " + calculated
+ "\n expected: " + expected);
}
double T = grid[j + optionTenor];
calculated = optionStat[j].mean();
expected = hwModel.discountBondOption(Option.Type.Call, strike, t, T);
if (Math.Abs(calculated - expected) > 0.0035)
{
QAssert.Fail("Failed to reproduce expected zero bond option prices"
+ "\n t: " + t
+ "\n T: " + T
+ "\n calculated: " + calculated
+ "\n expected: " + expected);
}
}
}
