private double fdCentral(
CdsAnalytic pricingCDS,
double cdsSpread,
CdsAnalytic[] curvePoints,
double[] spreads,
double[] deltaSpreads,
IsdaCompliantYieldCurve yieldCurve,
CdsPriceType priceType) {
int n = curvePoints.length;
double[] spreadUp = new double[n];
double[] spreadDown = new double[n];
for (int i = 0; i < n; i++) {
spreadUp[i] = spreads[i] + deltaSpreads[i];
spreadDown[i] = spreads[i] - deltaSpreads[i];
}
IsdaCompliantCreditCurve curveUp =
_curveBuilder.calibrateCreditCurve(curvePoints, spreadUp, yieldCurve);
IsdaCompliantCreditCurve curveDown =
_curveBuilder.calibrateCreditCurve(curvePoints, spreadDown, yieldCurve);
double up = _pricer.pv(pricingCDS, yieldCurve, curveUp, cdsSpread, priceType);
double down = _pricer.pv(pricingCDS, yieldCurve, curveDown, cdsSpread, priceType);
return up - down;
}
/**
* The bucked CS01 (or credit DV01) by shifting each market par-spread in turn. This takes an
* extraneous yield curve, a set of reference CDSs (marketCDSs) and their par-spreads (expressed
* as <b>fractions not basis points</b>) and bootstraps a credit (hazard) curve - the target CDS
* is then priced with this credit curve. This is then repeated with each market spreads bumped in
* turn. The result is the vector of differences (bumped minus base price) divided by the bump
* amount.<br>
* For small bumps (<1e-4) this approximates $$\frac{\partial V}{\partial S_i}$$ where $$S_i$$ is
* the spread of the $$1^{th}$$ market CDS<br>
*
* @param cds analytic description of a CDS traded at a certain time
* @param cdsCoupon The <b>fraction</b> spread of the CDS
* @param yieldCurve The yield (or discount) curve
* @param marketCDSs The market CDSs - these are the reference instruments used to build the
* credit curve
* @param marketParSpreads The <b>fractional</b> par-spreads of the market CDSs
* @param fracBumpAmount The fraction bump amount, so a 1pb bump is 1e-4
* @param shiftType ABSOLUTE or RELATIVE
* @return The credit CS01
*/
public double[] bucketedCS01FromParSpreads(
CdsAnalytic cds,
double cdsCoupon,
IsdaCompliantYieldCurve yieldCurve,
CdsAnalytic[] marketCDSs,
double[] marketParSpreads,
double fracBumpAmount,
ShiftType shiftType) {
ArgChecker.notNull(cds, "cds");
ArgChecker.noNulls(marketCDSs, "curvePoints");
ArgChecker.notEmpty(marketParSpreads, "spreads");
ArgChecker.notNull(yieldCurve, "yieldCurve");
ArgChecker.notNull(shiftType, "shiftType");
ArgChecker.isTrue(Math.abs(fracBumpAmount) > 1e-10, "bump amount too small");
int n = marketCDSs.length;
ArgChecker.isTrue(n == marketParSpreads.length, "speads length does not match curvePoints");
CdsPriceType priceType = CdsPriceType.DIRTY;
IsdaCompliantCreditCurve baseCurve =
_curveBuilder.calibrateCreditCurve(marketCDSs, marketParSpreads, yieldCurve);
double basePrice = _pricer.pv(cds, yieldCurve, baseCurve, cdsCoupon, priceType);
double[] res = new double[n];
for (int i = 0; i < n; i++) {
double[] temp = makeBumpedSpreads(marketParSpreads, fracBumpAmount, shiftType, i);
IsdaCompliantCreditCurve bumpedCurve =
_curveBuilder.calibrateCreditCurve(marketCDSs, temp, yieldCurve);
double price = _pricer.pv(cds, yieldCurve, bumpedCurve, cdsCoupon, priceType);
res[i] = (price - basePrice) / fracBumpAmount;
}
return res;
}
/**
* The bucked CS01 (or credit DV01) by a shift of each the market spread in turn. This takes an
* extraneous yield curve, a set of reference CDSs (marketCDSs) and their market quotes and
* bootstraps a credit (hazard) curve - the target CDS is then priced with this credit curve. This
* is then repeated with each market spreads bumped in turn by some amount. The result is the
* array of differences (bumped minus base price) is divided by the bump amount.<br>
* This can take quotes as ParSpread, PointsUpFront or QuotedSpread (or some mix). For
* par-spreads, these are bumped and a new credit curve built; for quoted-spreads, there are
* bumped and a new curve build be first converting to PUF; and finally for PUF, these are
* converted to quoted spreads, bumped and converted back to build the credit curve.
*
* @param cds analytic description of a CDS traded at a certain time - it is this CDS that we are
* calculation CDV01 for
* @param cdsCoupon the coupon of the traded CDS (expressed as <b>fractions not basis points</b>)
* @param yieldCurve The yield (or discount) curve
* @param marketCDSs The market CDSs - these are the reference instruments used to build the
* credit curve
* @param quotes The quotes for the market CDSs - these can be ParSpread, PointsUpFront or
* QuotedSpread (or any mixture of these)
* @param fracBumpAmount The fraction bump amount, so a 1pb bump is 1e-4
* @return The bucketed credit DV01
*/
public double[] bucketedCS01FromPillarQuotes(
CdsAnalytic cds,
double cdsCoupon,
IsdaCompliantYieldCurve yieldCurve,
CdsAnalytic[] marketCDSs,
CdsQuoteConvention[] quotes,
double fracBumpAmount) {
ArgChecker.notNull(cds, "cds");
ArgChecker.noNulls(marketCDSs, "curvePoints");
ArgChecker.noNulls(quotes, "quotes");
ArgChecker.notNull(yieldCurve, "yieldCurve");
ArgChecker.isTrue(Math.abs(fracBumpAmount) > 1e-10, "bump amount too small");
int n = marketCDSs.length;
ArgChecker.isTrue(n == quotes.length, "speads length does not match curvePoints");
IsdaCompliantCreditCurve baseCurve =
_curveBuilder.calibrateCreditCurve(marketCDSs, quotes, yieldCurve);
double basePrice = _pricer.pv(cds, yieldCurve, baseCurve, cdsCoupon);
double[] res = new double[n];
for (int i = 0; i < n; i++) {
CdsQuoteConvention[] bumpedQuotes =
bumpQuoteAtIndex(marketCDSs, quotes, yieldCurve, fracBumpAmount, i);
IsdaCompliantCreditCurve bumpedCurve =
_curveBuilder.calibrateCreditCurve(marketCDSs, bumpedQuotes, yieldCurve);
double price = _pricer.pv(cds, yieldCurve, bumpedCurve, cdsCoupon);
res[i] = (price - basePrice) / fracBumpAmount;
}
return res;
}
/**
* The bucked CS01 (or credit DV01) on a set of CDSS by bumping each quoted (or flat) spread in
* turn. This takes an extraneous yield curve, a set of reference CDSs (marketCDSs) and their
* quoted (or flat) spreads (expressed as <b>fractions not basis points</b>) and bootstraps a
* credit (hazard) curve - the target CDS is then priced with this credit curve. This is then
* repeated with each market spreads bumped in turn. The result is the vector of differences
* (bumped minus base price) divided by the bump amount.<br>
* For small bumps (<1e-4) this approximates $$\frac{\partial V}{\partial S_i}$$ for a flat curve
* where $$S_i$$
*
* @param cds a set of analytic description of CDSs traded at a certain times
* @param dealSpread The <b>fraction</b> spread of the CDS
* @param yieldCurve The yield (or discount) curve
* @param marketCDSs The market CDSs - these are the reference instruments used to build the
* credit curve
* @param quotedSpreads The <b>fractional</b> spreads of the market CDSs
* @param fracBumpAmount The fraction bump amount, so a 1pb bump is 1e-4
* @param shiftType ABSOLUTE or RELATIVE
* @return The bucked CS01 for a set of CDSs
*/
public double[][] bucketedCS01FromQuotedSpreads(
CdsAnalytic[] cds,
double dealSpread,
IsdaCompliantYieldCurve yieldCurve,
CdsAnalytic[] marketCDSs,
double[] quotedSpreads,
double fracBumpAmount,
ShiftType shiftType) {
ArgChecker.noNulls(cds, "cds");
ArgChecker.noNulls(marketCDSs, "curvePoints");
ArgChecker.notEmpty(quotedSpreads, "spreads");
ArgChecker.notNull(yieldCurve, "yieldCurve");
ArgChecker.notNull(shiftType, "shiftType");
ArgChecker.isTrue(Math.abs(fracBumpAmount) > 1e-10, "bump amount too small");
int nMarketCDSs = marketCDSs.length;
ArgChecker.isTrue(
nMarketCDSs == quotedSpreads.length, "speads length does not match curvePoints");
CdsPriceType priceType = CdsPriceType.DIRTY;
double[] premiums = new double[nMarketCDSs];
Arrays.fill(premiums, dealSpread); // assume the premiums of all CDS are equal
int nTradeCDSs = cds.length;
double[] puf =
_pufConverter.quotedSpreadsToPUF(marketCDSs, premiums, yieldCurve, quotedSpreads);
// TODO not needed
IsdaCompliantCreditCurve baseCurve =
_curveBuilder.calibrateCreditCurve(marketCDSs, premiums, yieldCurve, puf);
double[] basePrices = new double[nTradeCDSs];
for (int j = 0; j < nTradeCDSs; j++) {
basePrices[j] = _pricer.pv(cds[j], yieldCurve, baseCurve, dealSpread, priceType);
}
double[] bumpedPUF = new double[nMarketCDSs];
double[][] res = new double[nTradeCDSs][nMarketCDSs];
for (int i = 0; i < nMarketCDSs; i++) { // Outer loop is over bumps
System.arraycopy(puf, 0, bumpedPUF, 0, nMarketCDSs);
double bumpedSpread = bumpedSpread(quotedSpreads[i], fracBumpAmount, shiftType);
bumpedPUF[i] =
_pufConverter.quotedSpreadToPUF(marketCDSs[i], premiums[i], yieldCurve, bumpedSpread);
// TODO a lot of unnecessary recalibration here
IsdaCompliantCreditCurve bumpedCurve =
_curveBuilder.calibrateCreditCurve(marketCDSs, premiums, yieldCurve, bumpedPUF);
for (int j = 0; j < nTradeCDSs; j++) {
double price = _pricer.pv(cds[j], yieldCurve, bumpedCurve, dealSpread, priceType);
res[j][i] = (price - basePrices[j]) / fracBumpAmount;
}
}
return res;
}
private double fdCreditDV01(
CdsAnalytic pricingCDS,
double cdsSpread,
CdsAnalytic[] curvePoints,
double[] spreadsUp,
double[] spreadsDown,
IsdaCompliantYieldCurve yieldCurve,
CdsPriceType priceType) {
IsdaCompliantCreditCurve curveUp =
_curveBuilder.calibrateCreditCurve(curvePoints, spreadsUp, yieldCurve);
IsdaCompliantCreditCurve curveDown =
_curveBuilder.calibrateCreditCurve(curvePoints, spreadsDown, yieldCurve);
double up = _pricer.pv(pricingCDS, yieldCurve, curveUp, cdsSpread, priceType);
double down = _pricer.pv(pricingCDS, yieldCurve, curveDown, cdsSpread, priceType);
return up - down;
}
/**
* The bucked CS01 (or credit DV01) by shifting each implied par-spread in turn. This takes an
* extraneous yield curve and a credit curve and a set of bucket CDSs (CDSs with maturities equal
* to the bucket points). Par-spreads at the bucket maturities are implied from the credit curve.
* These spreads form pseudo market spreads to bootstraps a new credit (hazard) curve - the target
* CDS is then priced with this credit curve. This is then repeated with each spreads bumped in
* turn. The result is the vector of differences (bumped minus base price) divided by the bump
* amount.
*
* @param cds analytic description of a CDS traded at a certain time
* @param cdsCoupon The <b>fraction</b> spread of the CDS
* @param bucketCDSs these are the reference instruments that correspond to maturity buckets
* @param yieldCurve The yield (or discount) curve
* @param creditCurve the credit curve
* @param fracBumpAmount The fraction bump amount, so a 1pb bump is 1e-4
* @return The credit DV01
*/
public double[] bucketedCS01FromCreditCurve(
CdsAnalytic cds,
double cdsCoupon,
CdsAnalytic[] bucketCDSs,
IsdaCompliantYieldCurve yieldCurve,
IsdaCompliantCreditCurve creditCurve,
double fracBumpAmount) {
ArgChecker.notNull(cds, "cds");
ArgChecker.noNulls(bucketCDSs, "bucketCDSs");
ArgChecker.notNull(creditCurve, "creditCurve");
ArgChecker.notNull(yieldCurve, "yieldCurve");
ArgChecker.isTrue(Math.abs(fracBumpAmount) > 1e-10, "bump amount too small");
int n = bucketCDSs.length;
double[] impSpreads = new double[n];
double[] t = new double[n];
for (int i = 0; i < n; i++) {
impSpreads[i] = _pricer.parSpread(bucketCDSs[i], yieldCurve, creditCurve);
t[i] = bucketCDSs[i].getProtectionEnd();
if (i > 0) {
ArgChecker.isTrue(t[i] > t[i - 1], "buckets must be assending");
}
}
int index = Arrays.binarySearch(t, cds.getProtectionEnd());
if (index < 0) {
index = -1 - index;
}
index = Math.min(index, n - 1);
IsdaCompliantCreditCurve baseCurve =
_curveBuilder.calibrateCreditCurve(bucketCDSs, impSpreads, yieldCurve);
double basePrice = _pricer.pv(cds, yieldCurve, baseCurve, cdsCoupon);
double[] res = new double[n];
for (int i = 0; i <= index; i++) { // don't bother calculating where there is no sensitivity
double[] bumpedSpreads = makeBumpedSpreads(impSpreads, fracBumpAmount, ShiftType.ABSOLUTE, i);
IsdaCompliantCreditCurve bumpedCurve =
_curveBuilder.calibrateCreditCurve(bucketCDSs, bumpedSpreads, yieldCurve);
double price = _pricer.pv(cds, yieldCurve, bumpedCurve, cdsCoupon);
res[i] = (price - basePrice) / fracBumpAmount;
}
return res;
}
/**
* The CS01 (or credit DV01) by a shift of the quoted (or flat) spread of the CDS <b>when the CDS
* is quoted as points up-front (PUF)</b>.<br>
* This simply converts the PUF quote to a quoted (or flat) spread then calls
* parallelCS01FromQuotedSpread
*
* @param cds analytic description of a CDS traded at a certain time - it is this CDS that we are
* calculation CDV01 for
* @param coupon the of the traded CDS (expressed as <b>fractions not basis points</b>)
* @param yieldCurve The yield (or discount) curve
* @param puf points up-front (as a fraction)
* @param fracBumpAmount The fraction bump amount <b>of the quoted (or flat) spread</b>, so a 1pb
* bump is 1e-4
* @return The credit DV01
*/
public double parallelCS01FromPUF(
CdsAnalytic cds,
double coupon,
IsdaCompliantYieldCurve yieldCurve,
double puf,
double fracBumpAmount) {
double bumpedQSpread =
_pufConverter.pufToQuotedSpread(cds, coupon, yieldCurve, puf) + fracBumpAmount;
IsdaCompliantCreditCurve bumpedCurve =
_curveBuilder.calibrateCreditCurve(cds, bumpedQSpread, yieldCurve);
double bumpedPrice = _pricer.pv(cds, yieldCurve, bumpedCurve, coupon);
return (bumpedPrice - puf) / fracBumpAmount;
}
public double parallelCS01FromCreditCurve(
CdsAnalytic cds,
double cdsCoupon,
CdsAnalytic[] pillarCDSs,
IsdaCompliantYieldCurve yieldCurve,
IsdaCompliantCreditCurve creditCurve,
double fracBumpAmount) {
ArgChecker.notNull(cds, "cds");
ArgChecker.noNulls(pillarCDSs, "pillarCDSs");
ArgChecker.notNull(creditCurve, "creditCurve");
ArgChecker.notNull(yieldCurve, "yieldCurve");
ArgChecker.isTrue(Math.abs(fracBumpAmount) > 1e-10, "bump amount too small");
int n = pillarCDSs.length;
double[] impSpreads = new double[n];
double[] t = new double[n];
for (int i = 0; i < n; i++) {
impSpreads[i] = _pricer.parSpread(pillarCDSs[i], yieldCurve, creditCurve);
t[i] = pillarCDSs[i].getProtectionEnd();
if (i > 0) {
ArgChecker.isTrue(t[i] > t[i - 1], "pillars must be assending");
}
}
IsdaCompliantCreditCurve baseCurve =
_curveBuilder.calibrateCreditCurve(pillarCDSs, impSpreads, yieldCurve);
double basePrice = _pricer.pv(cds, yieldCurve, baseCurve, cdsCoupon);
double[] bumpedSpreads = makeBumpedSpreads(impSpreads, fracBumpAmount, ShiftType.ABSOLUTE);
IsdaCompliantCreditCurve bumpedCurve =
_curveBuilder.calibrateCreditCurve(pillarCDSs, bumpedSpreads, yieldCurve);
double price = _pricer.pv(cds, yieldCurve, bumpedCurve, cdsCoupon);
double res = (price - basePrice) / fracBumpAmount;
return res;
}
