Why is the NPV of this FX Forward 0?

Question

I've checked similar questions and answers but even after setting the evaluation date in ql.settings I still get zero. Like another poster, I also have the QL cookbook and have read everything I could find, but still struggling. Thanks for any help!

import QuantLib as ql 
calc_date= ql.Date(21,ql.July,2023)
ql.Settings.instance().setEvaluationDate(calc_date)

dayConvention = ql.Thirty360(ql.Thirty360.BondBasis)
calendar = ql.UnitedStates(ql.UnitedStates.NYSE)

trade_date = ql.Date(20,ql.July,2023)
maturityDate = ql.Date(4,ql.August,2023)

spotDates = [ql.Date(20,ql.July,2023), ql.Date(4,ql.August,2023), ql.Date(4,ql.August,2024)]
spotRates = [0.01318, 00.01318,0.01318]

compounding = ql.Simple
compoundingFrequency = ql.Annual

spotCurve = ql.ZeroCurve(spotDates, spotRates, dayConvention, calendar, ql.Linear(), compounding, compoundingFrequency)
spotCurve.enableExtrapolation()

spotCurveHandle = ql.YieldTermStructureHandle(spotCurve)

index = ql.USDLibor(ql.Period('1W'), spotCurveHandle)
index.addFixing(ql.Date(18, ql.July, 2023),0.01318)
# index.addFixing(ql.Date(26, 6, 2020), 0.05)
notional = 54760000
rate = 1.37825/100

fra = ql.ForwardRateAgreement(trade_date, maturityDate, ql.Position.Long, rate, notional, index, spotCurveHandle)
print('NPV:', fra.NPV())

Answer 1

This is not an FX Forward but a Forward Rate Agreement (a rates product). I'm not sure if QuantLib has a FX Forward pricer but they do have one for FX swaps (see FXSwapRateHelper).

Now, to get a non-zero NPV you probably want to add a valuation date before the settlement date:

for day in [18, 19, 20]:
    ql.Settings.instance().evaluationDate = ql.Date(day, 7, 2023)
    fra = ql.ForwardRateAgreement(trade_date, maturityDate, ql.Position.Long, rate, notional, index, spotCurveHandle)
    print('NPV:', round(fra.NPV(), 2), "Expired:", fra.isExpired())

Which gives:

NPV: -1373.95 Expired: False
NPV: -1373.95 Expired: False
NPV: 0.0 Expired: True

Remember that a FRA pays at the beginning of the period (see e.g. this paper). This is also explained in the QL documentation here: "the FRA settles and expires on the valueDate, not on the (later) maturityDate". The life cycle looks as follows: