//-------------------------------------------------------------------------
/// <summary>
/// Calculates the present value sensitivity of the swaption to the rate curves.
/// <para>
/// The present value sensitivity is computed in a "sticky strike" style, i.e. the sensitivity to the
/// curve nodes with the volatility at the swaption strike unchanged. This sensitivity does not include a potential
/// change of volatility due to the implicit change of forward rate or moneyness.
///
/// </para>
/// </summary>
/// <param name="swaption"> the swaption </param>
/// <param name="ratesProvider"> the rates provider </param>
/// <param name="swaptionVolatilities"> the volatilities </param>
/// <returns> the point sensitivity to the rate curves </returns>
public virtual PointSensitivityBuilder presentValueSensitivityRatesStickyStrike(ResolvedSwaption swaption, RatesProvider ratesProvider, SwaptionVolatilities swaptionVolatilities)
{
validate(swaption, ratesProvider, swaptionVolatilities);
double expiry = swaptionVolatilities.relativeTime(swaption.Expiry);
ResolvedSwap underlying = swaption.Underlying;
ResolvedSwapLeg fixedLeg = this.fixedLeg(underlying);
if (expiry < 0d)
{ // Option has expired already
return(PointSensitivityBuilder.none());
}
double forward = SwapPricer.parRate(underlying, ratesProvider);
ValueDerivatives annuityDerivative = SwapPricer.LegPricer.annuityCashDerivative(fixedLeg, forward);
double annuityCash = annuityDerivative.Value;
double annuityCashDr = annuityDerivative.getDerivative(0);
LocalDate settlementDate = ((CashSwaptionSettlement)swaption.SwaptionSettlement).SettlementDate;
double discountSettle = ratesProvider.discountFactor(fixedLeg.Currency, settlementDate);
double strike = calculateStrike(fixedLeg);
double tenor = swaptionVolatilities.tenor(fixedLeg.StartDate, fixedLeg.EndDate);
double volatility = swaptionVolatilities.volatility(expiry, tenor, strike, forward);
PutCall putCall = PutCall.ofPut(fixedLeg.PayReceive.Receive);
double price = swaptionVolatilities.price(expiry, tenor, putCall, strike, forward, volatility);
double delta = swaptionVolatilities.priceDelta(expiry, tenor, putCall, strike, forward, volatility);
// Backward sweep
PointSensitivityBuilder forwardSensi = SwapPricer.parRateSensitivity(underlying, ratesProvider);
PointSensitivityBuilder discountSettleSensi = ratesProvider.discountFactors(fixedLeg.Currency).zeroRatePointSensitivity(settlementDate);
double sign = swaption.LongShort.sign();
return(forwardSensi.multipliedBy(sign * discountSettle * (annuityCash * delta + annuityCashDr * price)).combinedWith(discountSettleSensi.multipliedBy(sign * annuityCash * price)));
}
//-------------------------------------------------------------------------
/// <summary>
/// Calculates the present value sensitivity of the swaption to the rate curves.
/// <para>
/// The present value sensitivity is computed in a "sticky strike" style, i.e. the sensitivity to the
/// curve nodes with the volatility at the swaption strike unchanged. This sensitivity does not include a potential
/// change of volatility due to the implicit change of forward rate or moneyness.
///
/// </para>
/// </summary>
/// <param name="swaption"> the swaption </param>
/// <param name="ratesProvider"> the rates provider </param>
/// <param name="swaptionVolatilities"> the volatilities </param>
/// <returns> the point sensitivity to the rate curves </returns>
public virtual PointSensitivityBuilder presentValueSensitivityRatesStickyStrike(ResolvedSwaption swaption, RatesProvider ratesProvider, SwaptionVolatilities swaptionVolatilities)
{
validate(swaption, ratesProvider, swaptionVolatilities);
double expiry = swaptionVolatilities.relativeTime(swaption.Expiry);
ResolvedSwap underlying = swaption.Underlying;
ResolvedSwapLeg fixedLeg = this.fixedLeg(underlying);
if (expiry < 0d)
{ // Option has expired already
return(PointSensitivityBuilder.none());
}
double forward = SwapPricer.parRate(underlying, ratesProvider);
double pvbp = SwapPricer.LegPricer.pvbp(fixedLeg, ratesProvider);
double strike = SwapPricer.LegPricer.couponEquivalent(fixedLeg, ratesProvider, pvbp);
double tenor = swaptionVolatilities.tenor(fixedLeg.StartDate, fixedLeg.EndDate);
double volatility = swaptionVolatilities.volatility(expiry, tenor, strike, forward);
PutCall putCall = PutCall.ofPut(fixedLeg.PayReceive.Receive);
double price = swaptionVolatilities.price(expiry, tenor, putCall, strike, forward, volatility);
double delta = swaptionVolatilities.priceDelta(expiry, tenor, putCall, strike, forward, volatility);
// Backward sweep
PointSensitivityBuilder pvbpDr = SwapPricer.LegPricer.pvbpSensitivity(fixedLeg, ratesProvider);
PointSensitivityBuilder forwardDr = SwapPricer.parRateSensitivity(underlying, ratesProvider);
double sign = swaption.LongShort.sign();
return(pvbpDr.multipliedBy(price * sign * Math.Sign(pvbp)).combinedWith(forwardDr.multipliedBy(delta * Math.Abs(pvbp) * sign)));
}
//-------------------------------------------------------------------------
/// <summary>
/// Calculates the present value of the swaption.
/// <para>
/// The result is expressed using the currency of the swaption.
///
/// </para>
/// </summary>
/// <param name="swaption"> the swaption </param>
/// <param name="ratesProvider"> the rates provider </param>
/// <param name="swaptionVolatilities"> the volatilities </param>
/// <returns> the present value </returns>
public virtual CurrencyAmount presentValue(ResolvedSwaption swaption, RatesProvider ratesProvider, SwaptionVolatilities swaptionVolatilities)
{
validate(swaption, ratesProvider, swaptionVolatilities);
double expiry = swaptionVolatilities.relativeTime(swaption.Expiry);
ResolvedSwap underlying = swaption.Underlying;
ResolvedSwapLeg fixedLeg = this.fixedLeg(underlying);
if (expiry < 0d)
{ // Option has expired already
return(CurrencyAmount.of(fixedLeg.Currency, 0d));
}
double forward = swapPricer.parRate(underlying, ratesProvider);
double numeraire = calculateNumeraire(swaption, fixedLeg, forward, ratesProvider);
double strike = calculateStrike(fixedLeg);
double tenor = swaptionVolatilities.tenor(fixedLeg.StartDate, fixedLeg.EndDate);
double volatility = swaptionVolatilities.volatility(expiry, tenor, strike, forward);
PutCall putCall = PutCall.ofPut(fixedLeg.PayReceive.Receive);
double price = numeraire * swaptionVolatilities.price(expiry, tenor, putCall, strike, forward, volatility);
return(CurrencyAmount.of(fixedLeg.Currency, price * swaption.LongShort.sign()));
}