Yield Curve
The relationship between Treasury bond yields across different maturities, most often observed as the spread between the 10-year and 2-year yields (T10Y2Y) or the 10-year and 3-month yields (T10Y3M).
The Treasury yield curve plots interest rates on U.S. government debt at different maturities, from 1-month bills through 30-year bonds. In a normal expansion, longer-dated bonds yield more than shorter-dated ones because investors demand compensation for locking money up for longer. When that relationship reverses — a shorter-dated bond yielding more than a longer-dated one — the curve is said to be inverted.
An inverted yield curve is the most reliable single-variable recession indicator in modern U.S. economic history — every recession since 1955 has been preceded by an inversion of the 10-year and 2-year spread, with a typical lead time of 6 to 24 months. The 10-year and 3-month spread has an even cleaner track record and is widely used by academic and central-bank recession models.
BullrunData exposes yield-curve spreads directly via the indicator endpoints for T10Y2Y and T10Y3M, and factors them into the composite recession probability calculation returned by /api/v1/model/probability.