Comprehensive Notes on Bond Fundamentals

Core Learning Objectives for Bond Fundamentals

To master the subject of bond fundamentals, a student must be able to understand the basic features of bonds that influence their risk, return, and valuation. This includes a comprehensive grasp of the current country structure of the world bond market and its evolution in recent years. It is essential to identify the major components of both the global and international bond markets and how the makeup of these markets varies significantly across major nations. Students must define bond ratings, explain their purpose, and distinguish between investment-grade and high-yield, or junk, bonds. Furthermore, one must detail the characteristics of major bond categories, including governments, Treasury Inflation-Protected Securities (TIPS), agencies, municipalities, and corporate issues. Specialized knowledge is required regarding recent developments in the U.S. corporate bond market, such as mortgage-backed securities (MBS), other asset-backed securities (ABS), zero-coupon and deep discount bonds, high-yield bonds, and structured notes. Finally, proficiency in interpreting market quotes for various bond categories, including governments, municipalities, and corporates, is necessary for practical application.

Defining the Global Bond Market Structure

The global bond market is an expansive and diverse landscape representing critical investment opportunities beyond equity markets. This study focuses on publicly issued, long-term, nonconvertible debt obligations from both public and private issuers within the United States and other major global financial centers. Bonds are traditionally considered fixed-income securities because they impose specific, fixed financial obligations on the issuer. Specifically, the issuer agrees to pay a fixed amount of interest periodically to the holder of record and to repay a fixed amount of principal, or par value, at the date of maturity. While interest is typically paid every six months, intervals can vary from one month to one year. The par value is rarely less than $1,000. Public debt is categorized by original maturity into three segments: the money market, which consists of short-term issues with maturities of one year or less; notes, which are intermediate-term issues with maturities between 1 and 10 years; and bonds, which are long-term obligations with maturities exceeding 10 years. As time passes, issues transition through these segments, which is significant because the remaining life of an issue is a primary determinant of its price volatility.

Intrinsic Features and Bond Characteristics

A bond is characterized by several intrinsic features, including its coupon, maturity, principal value, and ownership type. The coupon indicates the nominal yield or interest income the investor receives. Maturity defines the lifespan, with term bonds having a single maturity date and serial obligation bonds, commonly used by municipalities, having multiple maturity dates across the issue. The principal or par value represents the original obligation, usually in increments of $1,000, though market values fluctuate above or below this based on prevailing interest rates. If market rates exceed the coupon, the bond sells at a discount; if they are lower, it sells at a premium. Ownership is either in bearer form, where the holder is the owner and clips physical coupons, or registered form, where the issuer maintains records and pays the owner directly. Unlike common stock, companies often have multiple bond issues outstanding. These can be secured (senior) bonds backed by specific property like real estate (mortgage bonds) or equipment (equipment trust certificates), or unsecured bonds known as debentures, backed only by the general credit of the issuer. Subordinated (junior) debentures have lower claims on income, while income bonds only pay interest if it is earned. Refunding issues are used to retire older debt prematurely. Research by Hickman (1958) suggest that collateral importance typically peaks only as default approaches, with quality ratings being the primary driver of yield differentials.

Indenture Provisions and Maturity Features

The bond indenture serves as the legal contract between the issuer and bondholder, with a trustee, often a bank, ensuring compliance. Key provisions include call options, which affect the bond's maturity. Freely callable bonds can be retired any time with 30 to 60 days' notice, while noncallable bonds cannot be retired early. Deferred call provisions prevent retirement for a set period, such as 5 to 10 years, after which the bond becomes freely callable. Callable bonds usually involve a call premium, representing an amount above par paid to the holder. Nonrefunding provisions prevent the use of lower-coupon debt to retire an issue, though other fund sources like excess cash or asset sales may still be used for early retirement. Sinking funds are another critical provision, requiring systematic debt payoff over the bond's life. This can involve retiring fixed or variable sums annually, sometimes starting after a deferment. Sinking fund retirements often occur through negotiations between the trustee and institutional holders at prices slightly above market value, though they can also be done via random calls.

Quantitative Analysis of Bond Returns

The rate of return for a bond is calculated based on price changes and contractual cash flows. The Holding Period Return (HPR) for bond $i$ during period $t$ is defined by the formula:

$HPR_{i,t} = \frac{P_{i,t+1} + Int_{i,t}}{P_{i,t}}$

In this equation, $P_{i,t+1}$ is the market price at the end of the period, $P_{i,t}$ is the price at the beginning, and $Int_{i,t}$ is the interest paid or accrued. Because interest is contractual, it accrues over time; thus, a sale between payment dates include accrued interest. The Holding Period Yield (HPY) is derived as:

$HPY = HPR - 1$

While interest is fixed, market forces determine bond prices, leading to capital gains or losses. Increased interest rate volatility since the 1960s has made these price variations a major component of overall bond returns.

Global Distribution and Comparative Market Size

The fixed-income market is significantly larger than listed equity exchanges like the NYSE, TSE, or LSE. In 2010, less than 10 percent of new U.S. security issues were equity, as corporations prefer internal funding or debt. According to Bank of America Merrill Lynch Global Research, the estimated total face value of the global bond market reached approximately $35,575,171\,\text{million}$ in 2010, up from $33,149,848\,\text{million}$ in 2009. The U.S. dollar remains the dominant currency, though its share dropped from 45 percent in 2002 to approximately 43.26 percent in 2010. The Euro sector, established in 1999, stabilized at around 30.32 percent. Other significant currencies include the Japanese Yen at 16.09 percent and the Pound Sterling at 4.44 percent. The market is categorized into five main segments: sovereign bonds, quasi and foreign governments (including agencies), securitized/collateralized bonds, corporate bonds, and high-yield/emerging market bonds. Japan’s market is dominated by sovereigns (81.4 percent), while the U.S. has a high percentage of securitized debt (27.6 percent).

Institutional Participation and Bond Ratings

Institutional investors account for 90 to 95 percent of bond trading. Life insurance companies favor corporate bonds, while commercial banks invest in municipals and government issues due to their short-term liability structures and tax status. Pension funds, being tax-free with long-term commitments, prefer high-yielding long-term government or corporate bonds. Bond ratings by agencies like Fitch, Moody’s, and Standard & Poor’s are essential for credit analysis. These agencies evaluate a firm's ability to service debt, correlating ratings with profitability, size, cash flow coverage, and financial leverage. Ratings range from AAA (Aaa) to D. Investment-grade bonds are those rated AAA through BBB (Baa), while speculative-grade (BB, B) and default-tier bonds (C, D) represent higher risk. Revisions to ratings typically occur in single-grade increments. High-yield bonds are also known as junk bonds. Split ratings occur when agencies disagree on an issue's quality. Some issues receive higher ratings through credit-enhancement devices like bank letters of credit or insurance.

Domestic and International Government Debt Instruments

U.S. Treasury obligations include T-bills (maturities under 1 year, sold at a discount), notes (1 to 10 years), and bonds (10 to 30 years). Interest is federally taxable but state and local exempt. Since 1989, all Treasury issues have been noncallable. Treasury Inflation-Protected Securities (TIPS) were introduced in 1997, with principal and interest indexed to the CPI-U. Principal is adjusted every six months with a three-month lag. For example, if a TIPS bond with a 3.50 percent coupon is issued, and the CPI increases by 1.5 percent in the first half-year, the accrued principal on a $1,000 bond becomes $1,000 \times (1 + 0.015) = 1,015.00$, and the semiannual interest payment becomes $0.0175 \times 1,015 = 17.76$. In Japan, the second-largest market, government bonds (JGBs) comprise over 50 percent of outstanding debt, with benchmark 10-year issues providing high liquidity. The U.K. market includes "gilts" (short, medium, and long), often issued via the tender method. The Eurozone market is collectively larger than the Japanese market, though issuing processes vary by country.

Agency and Municipal Bond Specifics

U.S. agencies like GNMA, FNMA, and FHLMC support legislative programs, such as housing. These are not typically direct government obligations but carry high credit quality. Municipal bonds are issued by local entities and categories into General Obligation (GO) bonds, backed by taxing power, and Revenue bonds, backed by project income. Interest is federally tax-exempt, requiring the calculation of an Equivalent Taxable Yield (ETY):

$ETY = \frac{i}{1 - t}$

If an investor in a 35 percent tax bracket ($t = 0.35$) considers a 5 percent municipal bond ($i = 0.05$), the calculation is:

$ETY = \frac{0.05}{1 - 0.35} = 0.0769\,\text{or}\,7.69\%$

Municipal bond insurance, provided by firms like MBIA and AMBAC, historically guaranteed payments but faced severe impairment during the 2007-2008 crisis when they began insuring subprime-linked CDOs, leading to massive downgrades and market disruption.

Corporate Bond Market and Structured Finance

The U.S. corporate bond market is dominated by utilities, followed by industrials and financial issues. Innovations include Mortgage Pass-Through Securities and Collateralized Mortgage Obligations (CMOs), which use tranches (Class A, B, C, and Z) to prioritize sequential principal payments and manage prepayment risk. Covered bonds, common in Europe, offer dual recourse to both the issuer and an asset pool. Asset-Backed Securities (ABS) have expanded to include Certificates for Automobile Receivables (CARS) and credit card-backed securities, which use revolving structures and lockout periods. Auction-Rate Securities, which attempted to set short-term rates for long-term funds, failed during the 2008 "flight to quality." Variable-rate notes offer floating coupons, typically 1 percent above a T-bill rate, and are redeemable at par. Collateralized Debt Obligations (CDOs) involve diversified pools of assets and tranches of varying credit quality, though they suffered immensely from subprime defaults and liquidity crises in 2007-2008.

High-Yield Bonds and Valuation Features

High-yield (junk) bonds are rated below BBB/Baa. Historically consisting of "fallen angels," the market was revolutionized in the 1980s by Drexel Burnham Lambert (DBL), which used them for small firms and leveraged buyouts (LBOs). By 2011, high-yield debt made up about 20 percent of U.S. corporate debt, with an average issue size over $460\,\text{million}$. Zero-coupon bonds make no interim payments and are valued as the present value of the final principal. For a $20\,\text{year}$, $10,000 par bond at an 8 percent semiannual discount rate, the price is:

$PV = 10,000 \times 0.208289 = 2,082.89$

International segments include Foreign bonds (e.g., Yankee bonds in USD, Samurai bonds in Yen, Bulldog bonds in Sterling) and Eurobonds (e.g., Eurodollars), which are sold outside the country of the currency's origin.

Interpreting Bond Quotes and Market Information

Bond transparency improved with the introduction of the Trade Reporting and Compliance Engine (TRACE) by NASD in 2004, which expanded reporting to 17,000 bonds within 30 minutes. Corporate bonds like Republic Services (RSG) are quoted as a percentage of par (e.g., 100.978) and evaluated based on their spread over U.S. Treasuries (measured in basis points). Treasury and agency quotes use 32nds; a quote of 112:06 indicates $112 + \frac{6}{32}\%$. All bonds, except preferred stock, trade on an accrued interest basis. For a bond with a 6 percent coupon ($\$30$ semiannual) where 2 months have elapsed since the last payment, the accrued interest is:

$Int_{acc} = \frac{2}{6} \times 30 = 10.00$

Specific listings may also include stripped securities (ci for coupon interest, np for note principal) and TIPS with accrued principal values.

Questions & Discussion

• What are some of the basic features of bonds that affect their risk, return, and value?

• What is the current country structure of the world bond market, and how has the makeup of the global bond market changed in recent years?

• What are the major components of the world bond market and the international bond market?

• How does the makeup of the bond market differ in major countries?

• What are bond ratings, and what is their purpose? What is the difference between investment-grade bonds and high-yield (junk) bonds?

• What are the characteristics of bonds in the major bond categories, such as governments (including TIPS), agencies, municipalities, and corporates?

• What are the important characteristics of corporate bond issues developed in the United States during the past decade, such as mortgage-backed securities, other asset-backed securities, zero-coupon and deep discount bonds, high-yield bonds, and structured notes?

• How do you read the quotes available for the alternative bond categories (e.g., governments, municipalities, and corporates)?