TL;DR. The yield curve plots U.S. Treasury yields against their maturities, from a few weeks out to 30 years. Most of the time it slopes upward; when it slopes downward — an “inversion” — it is the bond market’s loudest single signal that growth, inflation, and Fed policy are out of sync. Every U.S. recession since the late 1960s has been preceded by an inversion of the 10-year minus 3-month spread, though the lead time has been highly variable.
What the yield curve actually is
The U.S. Treasury issues debt across a ladder of maturities. TreasuryDirect lists bills at 4, 6, 8, 13, 17, 26, and 52 weeks; notes at 2, 3, 5, 7, and 10 years; and bonds at 20 and 30 years. The Federal Reserve’s H.15 release reports daily constant-maturity yields for 1, 3, and 6 months and for 1, 2, 3, 5, 7, 10, 20, and 30 years.
The “yield curve” is simply those yields plotted against their maturity. The y-axis is yield in percent. The x-axis is time to maturity, scaled by convention so 3 months sits close to 2 years and 10 years sits close to 30. Every business day at 4:15 p.m. Eastern, the Fed publishes a fresh set of points; the market trades them continuously in between.
Why the shape carries information
A Treasury yield is the return an investor accepts for locking up money for a fixed period. That yield contains three things stacked on top of each other:
- Expected short rates. The market’s best guess at the average overnight rate the Fed will set over the life of the bond.
- A term premium. Extra yield investors demand for bearing duration risk — the chance that rates, inflation, or supply surprise them before maturity.
- Liquidity and supply effects. Smaller on-the-run versus off-the-run premia and one-off Treasury-supply quirks at specific maturities.
That is why the curve is more than a chart of bond prices. Its slope is a real-time read on where the bond market thinks the Fed and the economy are heading. A useful analogy: the curve is to the bond market what the VIX is to equities — a single picture that summarizes how the asset class is pricing the next few years.
The three classic shapes
There are three textbook shapes, illustrated above and tabulated below.
- Normal (upward sloping). Long yields are higher than short yields. The market expects steady growth and a positive term premium. This is the default shape across most of post-war U.S. history.
- Flat. Short and long yields are roughly equal. The market is in transition — growth expectations are softening, or the Fed is near the end of a hiking cycle.
- Inverted (downward sloping). Short yields are higher than long yields. The market expects the Fed to cut, usually because growth or inflation is about to weaken.
| Maturity | Normal curve | Flat curve | Inverted curve |
|---|---|---|---|
| 3-month | 3.00% | 4.00% | 5.25% |
| 2-year | 3.50% | 4.00% | 4.75% |
| 5-year | 3.90% | 4.05% | 4.30% |
| 10-year | 4.25% | 4.10% | 4.00% |
| 30-year | 4.60% | 4.15% | 3.95% |
| 10y minus 3m spread | +1.25% | +0.10% | −1.25% |
A simple worked example: reading a single day’s curve
Suppose on a given day the 3-month bill yields 5.25%, the 2-year note yields 4.75%, the 10-year note yields 4.00%, and the 30-year bond yields 3.95%. Two quick reads:
- The 10y minus 3m spread is −1.25%. Short rates exceed long rates. The market expects the Fed to cut materially over the next year or two.
- The 30y is below the 10y by only 5 basis points. Long-end investors are not demanding much extra yield to stretch from 10 to 30 years, suggesting muted long-run inflation expectations.
Two numbers, two macro signals. That is the entire point of looking at the curve instead of any single rate in isolation.
Why inversions get so much attention
Empirically, an inversion of the 10-year minus 3-month spread has preceded every U.S. recession since the late 1960s. The Federal Reserve Bank of New York publishes a recession-probability model derived from exactly that spread; the model and its rationale are described on the bank’s yield-curve research page. The intuition is simple: if investors are willing to lock up 10-year money at less than the rate on a 3-month bill, they must believe short rates will fall — and short rates typically fall because the Fed is cutting to support a slowing economy.
The 10-year minus 2-year spread tells a similar story and is the version most often quoted on financial news because it flips first. The St. Louis Fed publishes both series daily as T10Y3M and T10Y2Y. Academic work by Arturo Estrella and Frederic Mishkin in the late 1990s established the 10y–3m spread as the workhorse forecasting variable; subsequent Fed research has revisited and broadly confirmed the relationship.
Common mistakes when reading the curve
Even seasoned investors fall into a small number of traps. Three to avoid:
- Treating inversion as a timing tool. Inversions have led recessions by anywhere from roughly six months to nearly two years. The signal is real; the timing is not.
- Confusing the cause of the inversion. A curve can invert because the long end is falling (growth fear) or because the short end is rising (Fed tightening). The macro implication is different, so always check which end moved.
- Ignoring the term premium. Estimates from the New York Fed’s Adrian-Crump-Moench (ACM) model show the term premium can be deeply negative for years at a time. When the premium is unusually negative, part of any inversion is mechanical rather than a pure growth signal.
How to read the curve day to day
A workable routine for non-specialists:
- Check the 10y–3m spread on FRED every week or two. It is the most-studied recession indicator.
- Cross-check with the 10y–2y spread. If both are deeply inverted, the signal is consistent.
- Note where on the curve the action is — front end (Fed-driven), belly (growth-driven), or long end (inflation-driven).
- Track the move, not just the level. A curve that re-steepens from a deep inversion is historically a late-cycle warning, not an all-clear.
Related concepts and what to learn next
- Bond duration and convexity — the mechanics behind why long-dated yields move the way they do.
- Term premium — the New York Fed’s ACM model is the most-cited estimate.
- The Fed’s Summary of Economic Projections “dot plot” — a quarterly snapshot of where Fed officials expect short rates to go, useful as a cross-check on what the curve is implying.
Sources
- Federal Reserve H.15, Selected Interest Rates (Daily)
- TreasuryDirect — Treasury bills
- U.S. Department of the Treasury — Interest Rate Statistics
- Federal Reserve Bank of New York — Yield Curve Research FAQ
- FRED — 10-Year minus 3-Month Treasury Spread (T10Y3M)
- FRED — 10-Year minus 2-Year Treasury Spread (T10Y2Y)
- NBER Business Cycle Dating Committee
Disclosure: This article was produced with AI assistance and reviewed before publication. It is for informational purposes only and is not investment advice.