Yield spreads explained: the gap between yields and what it reveals

The headline yield on a bond tells the investor what they will earn if they hold to maturity (or what they expect to earn given current market price). The spread between two yields tells them something different: how the market is pricing the relative risk between the two bonds. Yield spreads—between credit grades, between maturities, between countries—encode information that no single yield can convey.

What yield spreads are

A yield spread is the difference between the yields on two fixed income instruments. The instruments are typically chosen so that the comparison is meaningful: a corporate bond's spread over the corresponding-maturity Treasury isolates credit risk; a 10-year Treasury's spread over a 2-year Treasury isolates the term premium; a foreign bond's spread over the domestic equivalent isolates country risk and currency expectations.

The metric is expressed in basis points (1 bp = 0.01 percentage point). A 200 bp spread means the higher-yielding instrument offers 2.00 percentage points more yield than the lower-yielding one. Spread movements over time—widening or tightening—are watched closely as indicators of changing market conditions in the relevant risk dimension.

Several spread types are commonly tracked. The most prominent for retail investors are credit spreads (corporate over government), term spreads (long over short within the same credit class), and country spreads (foreign over domestic government).

How each spread type works

Credit spread. The yield on a corporate bond above the corresponding-maturity Treasury isolates the market's pricing of the corporate's default risk relative to the (effectively default-free) Treasury. Widening credit spreads indicate that the market expects more defaults, more uncertainty, or simply demands more compensation for credit risk. Tightening credit spreads indicate the opposite. The credit spread is one of the most-watched economic indicators, particularly the BBB-corporate-over-10-year-Treasury spread that has historically moved before recessions.

Term spread. The yield on a long-maturity bond above the corresponding short-maturity bond of the same credit quality isolates the term premium—the compensation investors require for locking in capital for longer periods. The most-watched is the US 10-year-minus-2-year Treasury spread. A positive term spread (long above short) is the historical norm; an inverted term spread (long below short) has historically been a reliable recession indicator, though with substantial variation in lead time.

Country spread. The yield on a foreign government bond above the domestic equivalent reflects the market's pricing of country risk—default risk for less-creditworthy issuers, currency-stability concerns, and expectations about future relative interest rate paths. Italy-Germany 10-year spreads, for instance, have been the canonical measure of European peripheral sovereign risk through the post-2010 period.

TED spread. The TED spread—the yield on three-month US Treasuries below the corresponding LIBOR (or, more recently, SOFR-based) bank-funding rate—measures interbank credit conditions. The TED spread spiked dramatically in October 2008 (to near 5%) as interbank lending froze; it is now a standard signal of bank-sector stress.

What the evidence shows

The yield-curve inversion as a recession indicator is the most-replicated finding in spread analysis. Estrella and Mishkin (1998) and subsequent work document that an inverted 10y-2y Treasury spread has preceded every US recession in the modern data, with lead times ranging from 6 to 24 months. The signal is not infallible—there have been false positives—but the absence of an inversion has historically been a strong indicator that a recession is not imminent.

Credit spreads as a leading indicator have a similar but less clean track record. BBB credit spreads above a defined long-run average have preceded most recessions, but the threshold has not been consistent and the lead time has varied. The signal is more useful as a corroboration of other indicators than as a standalone forecast.

For portfolio construction, spread movements affect the relative pricing of the asset classes the spreads describe. A widening credit spread is, by definition, an opportunity to buy corporates at a lower price relative to Treasuries; a tightening spread is the inverse. The empirical case for systematic spread-trading strategies is mixed—the strategies have produced returns in some periods and losses in others—but spread information at minimum should inform the timing of fixed income allocation decisions.

Limitations and trade-offs

Spread movements can reflect several different economic forces, and disentangling them is not always possible. A widening credit spread can signal rising default risk, falling risk appetite (the same default rate priced more conservatively), or technical flow effects (forced selling by an institutional investor). The headline movement does not distinguish between these causes, and investors who interpret all spread widening as a recession signal will be wrong some fraction of the time.

Spread comparisons across countries and currencies require care. A 200 bp spread between an EUR-denominated and a USD-denominated bond reflects credit and currency dynamics together, not credit alone. To isolate credit risk in a cross-currency comparison, investors typically use spread metrics computed against domestic-currency benchmarks for each issuer.

Finally, spreads are not always informative. In regimes of unusual central-bank intervention—quantitative easing, yield-curve control, large-scale asset purchases—the standard relationships between spreads and underlying economic variables can break down. The 2010s post-QE period produced sustained periods in which traditional spread-based recession indicators delivered no useful signal, because the absolute level of yields was being managed by central-bank policy rather than emerging from market clearing.

Yield spreads in pfolio

Yield spreads—the gap between yields on two fixed income instruments—are implicit in pfolio's fixed income universe rather than reported as a standalone metric. Investors can compare the yield characteristics of any two bond ETFs or bond futures on the Assets page, and the spread between them can be tracked over time using the price series for each instrument.

Related articles

• The yield curve: what the shape of interest rates across maturities reveals
• Credit risk and credit spreads: how default risk is priced into bond markets
• Government bonds vs corporate bonds: risk, return, and their role in a portfolio
• Fixed income investing explained: bonds, yield, and stability in a portfolio