Definition
The yield curve is the pattern of interest rates by maturity for bonds of comparable credit quality, most commonly US Treasury securities, showing what the market currently pays lenders across short-term, medium-term, and long-term bonds.
Why it matters
The yield curve is one of the most-watched summary of the interest rate environment — it determines what lenders receive, what borrowers pay, and what discount rates apply across the fixed-income landscape. Every lifetime income arrangement priced by an insurer is sensitive to some point on the yield curve, because the arrangement's pricing is set against the yield the insurer expects to earn on the assets backing it.
How it works
The yield curve is typically plotted with maturity on the horizontal axis (from three months to thirty years is the standard US Treasury range) and yield on the vertical axis (the annualized rate the security pays if held to maturity). At any given moment, the market prices these securities and the resulting yields form a curve. The typical shape is upward-sloping — longer maturities pay higher yields — reflecting the compensation lenders demand for tying up capital for longer periods and bearing greater interest rate risk over the holding period. The curve can flatten (long yields close to short yields) or invert (long yields below short yields) under specific macroeconomic conditions. For example, a Treasury yield curve with 4.0% at the 2-year maturity, 4.2% at the 5-year, and 4.5% at the 10-year is a normal, gently upward-sloping curve; the same curve with the 2-year at 4.8% and the 10-year at 4.5% is inverted by 30 basis points.
In practice
Individuals encounter the yield curve indirectly through the pricing of nearly every fixed-income product they consider. A CD's rate reflects the yield at its maturity; a mortgage rate reflects the long end of the curve; an immediate annuity's payout rate reflects the yield the carrier expects to earn on the assets backing the contract. When commentators refer to "rates" rising or falling, they typically mean movement in some point on the yield curve — most often the 10-year Treasury yield. For an individual considering an annuity, the operative question is what part of the curve is embedded in the pricing. A professional working from the cost-of-income framework can indicate which maturity segment dominates a given quote and how sensitive the pricing is to changes at that point.
In the Longevity Standard Framework
The yield curve is the structural mechanism underlying the discount rate environment within which the Longevity Standard framework operates. Cost of income for any lifetime income arrangement is evaluated against a discount rate anchored to some point on the yield curve — typically the yield at the maturity closest to the planning horizon, so that for a focal individual planning from age 67 to age 90, the analytically relevant segment is roughly the 20-to-30-year portion of the curve. Changes in the shape and level of the curve translate directly into changes in cost of income and in the realized value of transferred-risk arrangements — a steeper long end generally lowers the cost of pooled and transferred income, while a flatter or inverted curve raises it. Insurer general account yields are set against the curve as well, which is why asset-side yield conditions and the term-structure of the curve are jointly determinative of the pricing an insurer can offer.
Related terms
- Term structure of interest rates
- Term premium
- Yield curve inversion
- Real interest rate
- Nominal interest rate
- Duration
- Investment yield
- Cost of income