The Yield Curve, Explained

What Is the Yield Curve?

A government issues bonds with many different maturities — some come due in three months, others in two years, ten years, or thirty years. Each of those bonds trades in the market every day, and each one carries its own yield (the annual return an investor earns by holding it). The yield curve is simply a snapshot of all those yields plotted on a single chart, with time-to-maturity on the horizontal axis and the yield percentage on the vertical axis.

Think of it as a photograph of the bond market's collective opinion about the future, taken at a specific moment. Because that opinion changes constantly, the curve shifts in shape and level every trading day. You can follow live government bond yields across maturities on the bonds data page.

The Three Basic Shapes

Normal (Upward-Sloping)

In ordinary times, short-term bonds carry lower yields than long-term bonds. This upward slope is called a normal yield curve. The logic is intuitive: lending money for thirty years is riskier than lending for three months, so investors demand extra compensation for the uncertainty — about inflation, about economic conditions, about whether the borrower will remain creditworthy. That extra compensation is called the term premium.

A normal curve is historically associated with a healthy, expanding economy. Growth is expected to continue, inflation is manageable, and there is no particular panic about the near future.

Flat

When short-term and long-term yields are close together — say, a two-year bond and a ten-year bond both yielding roughly the same percentage — the curve is described as flat. A flat curve often appears during a transition: the central bank has been raising short-term rates, the long end hasn't moved as much, and the two ends are converging. Economists read a flattening curve as a sign that markets are uncertain about the growth outlook.

Inverted

An inverted yield curve — where short-term yields are higher than long-term yields — is the shape that attracts the most attention. It means investors are willing to accept a lower return for locking their money away for a decade than for lending it for just a few months. That only makes sense if they expect rates (and economic activity) to fall significantly in the future. Historically, an inverted curve has often preceded recessions, which is why it is closely watched. The dedicated guide to yield-curve inversion covers that signal in full.

Short End vs. Long End: Two Different Forces

Understanding the curve means understanding that the two ends respond to different things.

The short end (maturities of roughly two years and under) is tightly anchored to the central bank's policy rate — the overnight interest rate that institutions like the Federal Reserve or the European Central Bank set directly. When a central bank raises rates, short-term bond yields typically rise quickly. When it cuts, they fall. The interest-rate decisions guide explains how that mechanism works.

The long end (ten years, thirty years) is driven far more by what investors expect over the long haul: future inflation, long-run economic growth, and the balance of supply and demand for bonds. A central bank can influence these expectations through communication, but it cannot simply set a thirty-year yield the way it sets an overnight rate. This is why the two ends can — and often do — move in different directions at the same time.

Reading Curve Moves: Steepening and Flattening

Market participants talk about the curve steepening (the gap between short and long yields widening) and flattening (that gap narrowing). But there are actually four distinct versions of these moves, depending on which end is doing the moving. The table below summarises them clearly.

The word "bull" or "bear" here refers to what is happening to bond prices overall, not to stocks. Because bond prices and yields move in opposite directions, falling yields = rising prices = a "bull" move for bonds.

The Most-Watched Spread: 2-Year vs. 10-Year

Traders and economists don't usually stare at the whole curve at once. Instead, they focus on the spread — the difference in yield — between two specific maturities. The most commonly cited is the 2-year/10-year spread (often written as the "2s10s"). Subtract the 2-year yield from the 10-year yield. A positive number means the curve is normal; a negative number means it is inverted at that point.

Other commonly tracked spreads include the 3-month/10-year and the 5-year/30-year. Different spreads can tell slightly different stories at the same moment, which is why economists often look at more than one. You can track these spreads live on the bonds page or cross-reference the data with events on the economic calendar.

The government bond yields guide explains the benchmark bonds — including the US 10-year Treasury — that serve as reference points for this analysis.

What the Curve Does Not Tell You

The yield curve is a powerful descriptive tool, but it has limits worth knowing. First, it reflects expectations, not certainties. Markets can be wrong, and have been. Second, the relationship between curve shape and economic outcomes has shifted over time as central banks have used unconventional tools like quantitative easing — buying large quantities of bonds directly — which can distort the long end of the curve in ways that make the traditional signals harder to read.

Third, the curve is one piece of a much larger mosaic. Economists typically read it alongside inflation data, GDP readings, credit markets, and leading indicators before drawing any conclusions. Checking the indicators page alongside yield data gives a more complete picture of the economic landscape.

Finally, volatility in the curve itself matters. A curve that moves dramatically from day to day signals uncertainty; a stable curve suggests markets have a clearer consensus about where the economy is heading. For context on how to interpret rapid moves in any market data, the guide on what volatility means is a useful companion read.