Fixed-Income Security

Quick Definition

A fixed-income security is a financial instrument that obligates the issuer to make predetermined interest payments (typically called coupons) to the investor on a regular schedule and to return the original principal at maturity. Bonds are the most common fixed-income securities. The term "fixed income" reflects the contractually defined payment stream, unlike stocks, whose dividends are discretionary and prices variable.

What It Means

Fixed-income securities exist because borrowers (governments, corporations, municipalities) need to raise capital and investors want predictable income. The investor lends money. The borrower promises fixed periodic payments in return. This contractual certainty, knowing exactly how much interest you will receive and when, distinguishes fixed income from equity investing.

Fixed income serves multiple portfolio roles: generating regular income, preserving capital, reducing portfolio volatility, and hedging against equity market downturns. For retirees living on portfolio income, fixed income often forms the core of their portfolio.

Types of Fixed-Income Securities

Key Fixed-Income Concepts

Coupon Rate vs. Yield

Price-Yield Relationship

Bond prices and yields move inversely. This is the most important fixed-income relationship:

Example: You buy a 10-year bond with a 4% coupon for $1,000. If rates rise to 6%, new bonds pay $60/year vs. your $40. Your bond becomes less attractive. Its market price falls to roughly $852 so that its YTM equals the new 6% market rate.

Duration: Measuring Interest Rate Sensitivity

Duration measures how sensitive a bond's price is to interest rate changes:

A bond fund with 7-year duration loses approximately 7% in price for every 1% rise in interest rates.

The 2022 example remains instructive: The iShares 20+ Year Treasury ETF (TLT) has approximately 17-year duration. When rates rose roughly 3% in 2022, TLT fell approximately 32%. That is painful for investors who thought long-term government bonds were "safe."

The 2026 Bond Market: A New Era for Yields

The bond market in 2026 looks fundamentally different from the post-2008 era of near-zero rates. Several structural forces are driving yields higher:

As of July 23, 2026, the 10-year Treasury yield reached 4.71%, its highest level since January 2025. Prior to the Iran conflict that began in late February 2026, the 10-year yield had dipped below 4%. The 30-year TIPS yield hit 2.97%, the highest since the security was reintroduced in 2010.

The 10-year breakeven inflation rate, a market-based gauge of expected inflation, stood at 2.28% as of late July 2026. This is below its 2.5% peak in early May and consistent with the Fed achieving its 2% inflation target over time. The surge in Treasury yields is being driven primarily by rising real yields, not inflation expectations.

Axios reported on July 23, 2026 that this bond sell-off reflects a world where governments and companies are scrambling for enormous amounts of capital to finance wide fiscal deficits, the AI infrastructure buildout, and more. The rate environment is being shaped by the supply of loanable funds (finite) and demand (seemingly limitless).

The CBO estimates that every 0.1 percentage point rise in rates, sustained over the coming decade, would increase government interest expense by $379 billion. If the recent rate moves are sustained, it implies approximately $1.8 trillion in additional interest costs over the coming decade.

Fixed-Income Credit Quality

Credit rating agencies assess the issuer's ability to make payments:

The Fixed-Income Yield Spectrum (July 2026)

The yield curve has flattened modestly in 2026. The 2s/10s spread narrowed to 29 basis points as of late June 2026, down from 69 basis points at the start of the year. The 3-month/10-year spread remained positive at 64 basis points.

Key Points to Remember

• Fixed-income securities provide contractually defined interest payments (coupons) and return of principal at maturity
• Bond prices and yields move inversely: rising rates mean falling bond prices
• Duration measures interest rate sensitivity. Higher duration means greater price volatility when rates change.
• Credit quality (AAA to D) determines default risk premium above the risk-free Treasury rate
• In 2026, the 10-year Treasury yield reached 4.71%, driven by fiscal deficits, AI capital demand, and geopolitical tensions rather than inflation fears
• The 30-year TIPS real yield of 2.97% is the highest since 2010, signaling a regime shift away from the low-rate era
• Fixed income plays the role of income generation, capital preservation, and equity hedge in diversified portfolios

Common Mistakes to Avoid

• Assuming all bonds are "safe": Short-term, high-quality bonds (T-bills, short-duration investment-grade) have very low default risk and low price volatility. Long-term bonds have significant interest rate risk. Their prices can fall 20 to 40% when rates rise sharply. The "safety" of bonds must always be qualified by both credit risk and duration risk.
• Ignoring the difference between a bond fund and an individual bond: An individual bond held to maturity returns par value regardless of price fluctuations. You receive your principal back. A bond fund has no maturity date. As rates rise, the fund's NAV falls and stays down indefinitely. For investors who need their principal back at a specific date, individual bonds offer certainty a fund cannot.
• Chasing yield without understanding credit risk: A high-yield bond paying 8% looks attractive until the issuer defaults and you lose principal. The 300 to 700 basis point premium over Treasuries exists because default risk is real. During recessions, high-yield default rates can spike to 10% or higher.
• Assuming the Fed controls all interest rates: The Fed controls short-term rates (the federal funds rate). Long-term Treasury yields are set by the market. In 2026, the Fed held rates at 3.50 to 3.75% while the 10-year Treasury climbed to 4.71%. The gap reflects market expectations about future growth, deficits, and inflation, not the Fed's current policy rate.

Related Concepts

Fixed-income securities connect to several other financial concepts. The yield curve plots Treasury yields across different maturities and its shape signals market expectations about growth and recession. Interest rates are the fundamental driver of bond prices through the inverse price-yield relationship. Duration measures a bond's sensitivity to rate changes. Inflation erodes the real return of fixed-rate bonds, which is why TIPS exist. The Federal Reserve influences short-term rates and, through quantitative easing or tightening, affects longer-term yields. Diversification is the reason fixed income belongs in most portfolios alongside equities.

Frequently Asked Questions

Q: Are bonds "safe"? A: It depends on which risk you mean. Short-term, high-quality bonds (T-bills, short-duration investment-grade) have very low default risk and low price volatility. Long-term bonds have significant interest rate risk. Their prices can fall 20 to 40% when rates rise sharply. The "safety" of bonds must always be qualified by both credit risk and duration risk. In 2026, 30-year TIPS are yielding nearly 3% in real terms, but their price can still fluctuate significantly with rate changes.

Q: What is the difference between a bond fund and individual bonds? A: An individual bond held to maturity returns par value regardless of price fluctuations. You receive your principal back. A bond fund has no maturity date. As rates rise, the fund's NAV falls and stays down indefinitely (it does not "recover" at maturity). For investors who need their principal back at a specific date, individual bonds offer certainty a fund cannot.

Q: Why do bond yields differ from coupon rates? A: The coupon rate is fixed at issuance. Yield changes as market interest rates change. When a bond trading at $900 pays a $50 coupon, the current yield is 5.56% even though the coupon rate is 5%. Yield-to-maturity also accounts for the gain of receiving $1,000 back at maturity after buying at $900, the full picture of total return.

Q: Why are Treasury yields rising in 2026 if inflation is near target? A: Unlike previous bond sell-offs driven by inflation fears, the 2026 rise reflects a structural shift in the supply and demand for capital. Massive fiscal deficits from the One Big Beautiful Bill Act, the AI infrastructure buildout, and the end of the post-GFC savings glut are all increasing demand for borrowed capital. The 10-year breakeven inflation rate is only 2.28%, consistent with the Fed's 2% target. The yield increase is being driven by rising real yields, not inflation expectations.