Yield Curve

The yield curve is the graph of Treasury yields across maturities on a single day: the 3-month bill on one end, the 30-year bond on the other. A normal curve slopes upward, because lending money for decades carries more uncertainty than lending it for weeks. A flat curve means short and long rates match. An inverted curve, with short-term yields above long-term, is the rare shape that has preceded every US recession since the late 1960s, which is why financial media treats it as a signal.

The two ends answer different questions. The short end sits where the Federal Reserve sets it, because bills mature into whatever the Fed does next. The long end prices decades of growth and inflation expectations, set by markets rather than by the committee. The curve inverts when the Fed holds short rates high while the long end anticipates the cuts that recessions bring: the shape is the market's opinion about the Fed's future, not a rule. The most watched measure is the gap between 10-year and 2-year Treasury yields.

The curve is built one auction at a time. Each Treasury maturity trades continuously in the secondary market, its yield is the return at the current price, and plotting those yields against their maturities draws the curve. The short end tracks the federal funds rate almost mechanically, because a 3-month bill's return is whatever the Fed sets for the next three months. The long end is a market price: decades of expected short rates plus a term premium, the compensation for lending long, net of the liquidity the 30-year carries.

The inversions happen at the junction. When the Fed hikes to fight inflation, the short end rises with it; if markets believe the policy will slow the economy and force cuts, the long end refuses to rise, and the gap turns negative. The 2s10s spread, the 10-year yield minus the 2-year, is the standard measurement, with the 3-month to 10-year gap the Federal Reserve's preferred version. Both inverted in 2022 as the fastest hiking cycle in four decades ran into a long end that priced the slowdown.

The track record is strong and the timing is not. Every US recession since the late 1960s was preceded by an inversion, usually 6 to 24 months ahead, with one false signal in the 1960s. The 2006 inversion preceded the 2007 recession by roughly a year and a half. The 2022 inversion stretched past two years, the longest on record, and the recession the pattern predicted arrived as a slowdown instead. A signal with a lag measured in years is a forecast with error bars, which is how it should be used.

The curve matters to an American investor in two practical ways. First, it is the rate menu: mortgage rates, savings yields, and bond returns all price off points on it, so the shape is what every borrowing and saving decision quotes against. Second, it is the one recession signal with a real track record, and a noisy one beats commentary, because it aggregates the bond market's money rather than anyone's opinion.

I watched a colleague named Brent (yes, that Brent) move his 401(k) to 100% cash the week the curve inverted in 2022, announcing the recession the curve had promised. The recession did not arrive; the S&P 500 rose roughly 25% in 2023 and again in 2024, and his cash earned 5% while the market compounded. The signal had a lag of years, and he had treated it as a deadline.

The highest-leverage thing most Americans can do is read the curve as context rather than a switch: let it inform bond maturities, since an inverted curve pays you to stay short, and let it calibrate expectations. Check the current yields with the bond yield calculator and price the ladder with the fixed income calculator.