Between coupon payment dates, the flat price (not full price) is equal to par value. Obtaining Par Rates from Spot Rates. Since the par curve is a sequence of yields-to-maturity such that each bond is priced at par value, then the formula to obtain par rates is the following: CFA Level 1: Spot Rate vs Forward Rate. Par curve is a set of yields-to-maturity on coupon bonds priced at par with similar credit ratings and different maturities. If consecutive spot rates are higher and higher, then the forward curve is above the spot curve.