Pricing & Curves

Curve architecture

Two on-chain templates back the curve system:

Template	Cardinality	Purpose
Oracle.Curve	One per (currency, kind) — keyed, archive-on-publish	Latest discount/projection curve
Oracle.CurveSnapshot	Append-only	Audit log + sparkline history

A "curve" is a sequence of (tenorDays, zeroRate) pillars under an interpolation strategy (LinearZero is the default). Discount factors are interpolated per tenor; projection curves additionally carry an indexId (e.g. USD-SOFR).

Why two templates

Canton's PublishDiscountCurve archives the previous Curve contract on every publish. The ACS holds exactly one curve per key — without CurveSnapshot, the frontend's useCurveStream would never see more than a single point.

useCurveStream merges:

1. CurveSnapshot ACS query (history)
2. Live Canton WebSocket (deltas)
3. localStorage mirror (page refresh resilience)

Per-(ccy, indexId) curve book

The pricing engine keeps a curve book keyed by (currency, indexId) so a single trade can discount cashflows off the right curve regardless of how many products it touches.

This was a pricing-correctness fix (2026-04-21): pricing strategies must resolve discount off ctx.book, not ctx.curve. The latter only holds the most recently fetched curve and produced wrong NPVs on multi-currency trades.

Floating-rate indices

Configured under floatingRateIndices::

USD-SOFR:
  currency: USD
  family: SOFR
  compounding: CompoundedInArrears
  lookback: 2
  floor: 0.0

Field	Meaning
family	SOFR, ESTR, LIBOR, ...
compounding	CompoundedInArrears, OvernightAverage, Simple, ...
lookback	Days lookback for in-arrears compounding
floor	Optional rate floor; null = no floor

CompoundedIndex semantics (gotcha)

Daml Finance's CompoundedIndex Act360 interprets each Observation as a cumulative compounded index value, not a raw overnight rate. Coupon for a period is:

coupon = obs(end) / obs(start) - 1

If you publish raw rates and read them as CompoundedIndex, the math silently produces nonsense.

For raw overnight rates, use a different referenceRateType or publish proper Index values.

NPV by family

IRS / OIS / BASIS:
  NPV = sum over cashflows of (DF(t) * notional * rate(t) * accrual(t))
       + per-leg sign (pay/receive)

XCCY:
  NPV per leg in its own ccy
  Reported NPV = sum of legs translated via FxSpot to reporting ccy

CDS:
  NPV = premium_leg_PV - contingent_leg_PV
  contingent_leg uses (defaultProb, recovery) from demo.cdsStub or live credit curve

Per-leg direction

Pricing-correctness fix: NPV must be aggregated with per-leg direction (Pay = -1, Receive = +1), not flipped at the trade level. Multi-leg products (XCCY especially) had silent sign errors before this.

Maturity anchor

CDS pricing uses maturityDate as the discount anchor — not today — so the present value remains stable across days as the trade ages. XCCY theta is filtered to the in-currency leg to avoid double-counting.

Where this lives

• Pricing engine: shared-pricing/ (vitest suite via make test-pricing)
• Strategies per family: shared-pricing/src/strategies/*
• Curve fetch + cache: app/src/features/workspace/hooks/use-pricing.ts
• On-chain curve templates: contracts/src/Oracle/