The yield curve and interest rates
5 min read · updated July 8, 2026
Interest rates are not a single number. There is a different rate for lending money for three months than for lending it for ten years, and the map of all those rates is one of the most watched pictures in finance. Once you can read it, a lot of market headlines stop being mysterious.
Start with the building block. When you buy a bond, you are lending money and getting paid to wait. The bond yield is the annual return you earn if you buy the bond and hold it until it pays you back in full. So a 2-year government bond yielding 4.5% means an investor who holds it to maturity, the date the loan comes due, earns about 4.5% a year on their money. Higher yield, more return for the lender, and also more the borrower has to pay.
Plotting yields against time
Now line up government bonds of different maturities and plot each one's yield against how long until it matures. That plot is the yield curve. It usually runs from very short maturities like a 3-month bill out to very long ones like a 30-year bond.
We use government bonds for this because they are treated as essentially free of default risk, so the curve shows the price of time alone, stripped of the risk that a particular company might not pay you back. The numbers below are illustrative yields, in percent, for a normal curve:
| Maturity | Yield |
|---|---|
| 3-month | 4.0 |
| 2-year | 4.5 |
| 10-year | 4.8 |
| 30-year | 5.0 |
A normal curve slopes up
Read that table top to bottom and the yield rises as maturity lengthens. That is a normal yield curve, and it is the usual shape. Lending for longer should pay more for two reasons. You are giving up access to your money for longer, and the further out you look, the more uncertain the world gets: inflation could climb, the economy could turn, rates could move against you. The extra yield investors demand for taking on that longer wait and uncertainty is called the term premium. It is why the long end normally sits above the short end.
The two ends of the curve are set by different forces. The Federal Reserve, the US central bank, sets the very short end almost directly through the policy rate it controls. The long end is set by the market: it reflects what investors collectively expect for growth and inflation over many years. So the short end is policy, and the long end is expectation.
When the curve inverts
Sometimes the picture flips. Long-term yields fall below short-term yields, and the curve slopes down instead of up. That is an inverted yield curve, and it is unusual. It typically means the Fed has pushed short-term rates high to cool the economy, while investors, expecting weaker growth and rate cuts ahead, accept lower yields to lock in the longer bonds now.
An inverted curve has preceded almost every US recession in recent decades, which is why it gets so much attention. It is a warning signal, not a guarantee, and the timing between the inversion and any slowdown can be long. But when the market is willing to earn less for lending longer, it is quietly betting the future looks worse than the present.
Thinking a rising yield curve is bad news because "rates are going up." An upward slope is the normal, healthy state. The unusual and worrying shape is the inverted one, where long-term yields sit below short-term. Get the direction right: normal slopes up, inverted slopes down, and inversion is the red flag.
Why bankers live and die by this
This is not an economics-class curiosity. The yield curve feeds directly into the work.
Remember from time value of money that every valuation starts with a risk-free rate, and that anchor is just a yield off the government curve. Move the curve and you move the rate used for discounting every future cash flow, so valuations shift across the whole market. The curve also sets what companies pay to borrow: a firm's cost of debt is built on top of the matching government yield plus a spread for its own credit risk. When the curve rises, borrowing gets more expensive, which cools M&A and financing activity. When it falls, cheap debt fuels deals.
You will not be asked to draw the curve, but you may be asked "what does an inverted yield curve signal?" or "what happens to valuations when rates rise?" Answer both crisply: an inversion is a classic recession warning, and rising rates lift the discount rate, which pushes present values down. Tie it back to the denominator in a DCF and you sound like you actually understand the plumbing, not just the headline.
Glossary
New to the lingo? Every term used above, in plain English.
- Bond yield
- The annual return an investor earns if they buy a bond and hold it until it repays in full at maturity. A higher yield means more return for the lender and a higher borrowing cost for the issuer.
- Maturity
- The date a bond or loan comes due and the borrower repays the principal in full. Bonds are grouped by how far off this date is, from short-term bills to 30-year bonds.
- Yield curve
- A chart of interest rates on government bonds across maturities. When short-term rates rise above long-term rates the curve inverts, which markets read as a recession warning.
- Inverted yield curve
- An unusual situation where long-term government yields fall below short-term yields, so the curve slopes down instead of up. It has preceded almost every recent US recession and is widely read as a warning signal.
- Federal Reserve
- The central bank of the United States, often called the Fed. It sets the short-term policy interest rate, which directly controls the very short end of the yield curve.
- Risk-free rate
- The return on an investment with essentially no risk, usually the yield on a long-term government bond. It is the starting point for the cost of equity.
- Cost of debt
- The rate a company pays to borrow. Because interest is tax-deductible, the after-tax cost of debt is what goes into WACC, and it is cheaper than equity.
- Discounting
- Converting a future cash flow into its present value by dividing by (1 + r) for each period. It is the reverse of compounding.
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