01What the curve is, in one sentence
It is the yield of the same issuer (a country's Treasury) across every maturity at once: one month, three, six, a year, two, five, ten, thirty. Plotted on a chart, they form a curve.
Its normal shape is upward sloping: lending for thirty years demands more yield than lending for three months, because there is more time for things to go wrong. When that relationship breaks, the market is saying something.
02What inversion actually means
An inverted curve means short maturities yield more than long ones. And what sits behind it is one specific expectation: that in a few years' time interest rates will be lower than they are now.
Nobody lends for ten years at 4% if they believe that in year two they will be able to lend at 6%. If they accept that 4%, it is because they expect nothing better to come along. And rates usually fall when the economy cools and the central bank cuts to revive it.
And there is a second piece that is almost never mentioned, although it changes the reading: the ten-year rate is not simply the average of expected short rates. It is that average plus a term premium: the extra demanded by someone lending for ten years instead of rolling over every six months, for inflation uncertainty, for liquidity, for who happens to be buying those bonds. That premium is not fixed: it rises and falls, and it can turn negative.
What that implies is uncomfortable and worth knowing: a curve can invert without anyone expecting cuts, simply because the term premium has compressed. The years when central banks bought long-dated debt on a large scale are the obvious example. When you read that «the curve is pricing recession», the honest question is how much of that inversion is rate expectations and how much is term premium. And separating them takes a model, not a subtraction.
03What the curve does not do
- It does not set a date. Historically, between inversion and the eventual recession there have been anywhere from six months to two years. An indicator with that margin is no use for deciding what to do this week.
- It is not always right. There have been inversions with no recession behind them. The line «it has never failed» only holds by carefully choosing which segments you look at and in which country.
- There is no single curve. «The curve» usually means the 10-year minus the 2-year, but 10-year minus 3-month is a different measure, it inverts at different moments, and it has its own defenders. When you read «the curve has inverted», ask which one.
- It does not mean the same everywhere. Debt structure, central bank policy and even who is buying the bonds change what the same shape means.
04Where to look at it for free
The two figures that actually matter are public and free, and it is worth knowing because plenty of services resell them:
- United States: the Treasury's daily series, with eleven maturities from one month to thirty years, all on a bond-equivalent basis, which is precisely what makes them comparable with each other.
- Euro area: the AAA-rated sovereign curve published by the European Central Bank, also daily and with eleven maturities.
And a warning that is rarely given: the euro area AAA curve is an aggregate, not a country. It is not the Bund, nor the Spanish bond, nor the Italian one. Anyone showing you «the European curve» as though it were a single issuer is flattening something that is not the same thing. The live yield of those national bonds: that one is paid data.
05How to use it without fooling yourself
- Watch the distance, not the level. The 10-year headline is almost always irrelevant; the spread against the 2-year is the signal.
- Watch the short end too. Whether the three-month to two-year segment is flat or inverted says more about what is expected of the central bank in the near term.
- Compare it against itself. A curve is read against where it was three and twelve months ago, not against an abstract idea of normality.
- Do not turn it into a decision. It is context for understanding what the market is pricing. Anyone using it to tell you what to buy is adding a conclusion the curve does not contain.
Frequently asked questions
What does an inverted yield curve mean?
It means short maturities yield more than long ones, which normally reflects an expectation that interest rates will be lower in a few years' time than they are now. It is associated with recession because rates usually fall when the economy cools. But the curve does not announce a recession: it reflects that many people expect one. And part of any inversion can come from a compressed term premium rather than from rate expectations, which is a different thing entirely.
Does an inverted curve always mean a recession is coming?
No. There have been inversions with no recession behind them, and the claim that it has never failed only holds by carefully choosing which segments and which country you look at. It also sets no date: historically the gap between inversion and the eventual recession has run from six months to two years, which makes it useless for deciding what to do this week.
Which spread is 'the' yield curve, 10y-2y or 10y-3m?
Both are used and they are not the same. The 10-year minus 2-year is the most quoted; the 10-year minus 3-month inverts at different moments and has its own defenders. When a headline says the curve has inverted, the useful question is which spread it means. The short end, three months to two years, says more about what is expected of the central bank in the near term.
Where can I find yield curve data for free?
Two official sources cover it. The US Treasury publishes a daily series with eleven maturities from one month to thirty years, on a bond-equivalent basis. The European Central Bank publishes the AAA-rated sovereign curve for the euro area, also daily and with eleven maturities. Note that the euro area AAA curve is an aggregate, not a single country: it is not the Bund, nor the Spanish or Italian bond.
Both yield curves (the US Treasury and the euro area AAA) are served in the Markets section with their source and their date, and labelled for what they are: the European one as an AAA aggregate, not as any one country's bond.
This is information and analysis, not financial advice, and it contains no recommendation to buy or sell. See the disclaimer.
