What Is a Bond?

A bond is a fixed-income security representing a loan made to an issuer (government or corporation). You lend money; the issuer pays you periodic interest and returns principal at maturity.

How Bonds Work

Example: Government bond

You buy a $1,000 Treasury bond at 4% interest maturing in 10 years.

• You pay: $1,000
• Annual interest: $40/year (4% of $1,000)
• At maturity (year 10): Receive $1,000 principal
• Total paid to you: $400 in interest + $1,000 principal = $1,400

This is straightforward lending: you know exactly what you'll receive.

Bond Components

Face value (par value): The amount borrowed. Usually $1,000.

Coupon rate: The interest rate paid. A 4% coupon means 4% of face value annually.

Maturity: When the loan ends. 2-year, 10-year, 30-year bonds.

Coupon payment frequency: Usually semi-annually. A 4% annual coupon pays $20 twice yearly.

Bond Pricing and Interest Rates

Bond prices fluctuate based on interest rates:

Example: You own a $1,000 bond paying 4% interest ($40/year)

Interest rates fall to 2%:

• New bonds pay only 2% ($20/year)
• Your 4% bond ($40/year) is more valuable
• Someone will pay premium for it (say $1,200) to get $40/year
• Your bond rises in price

Interest rates rise to 6%:

• New bonds pay 6% ($60/year)
• Your 4% bond ($40/year) is less valuable
• You must discount it (say $800) for someone to accept lower return
• Your bond falls in price

Key relationship: Interest rates up → bond prices down | Interest rates down → bond prices up

Bond Types

Government bonds:

• Issued by governments
• Backed by taxation power
• Very safe (U.S. government default is nearly impossible)
• Low interest rates (3-5%)

Corporate bonds:

• Issued by companies
• Backed by company cash flows
• Risk varies by company (Apple's bonds safer than startup's)
• Higher rates (4-7%)

High-yield bonds (junk bonds):

• Issued by risky companies
• High default risk
• High interest rates (8-12%)
• Can lose significant value if company defaults

Yield vs. Coupon

Coupon: The stated interest rate (4%)

Yield: The actual return based on current price

Example: $1,000 bond, 4% coupon, current price $800

• Coupon: 4% ($40/year)
• Yield: $40 ÷ $800 = 5%

Yield is what matters to buyers. If you buy at $800, you get a 5% yield (not 4%).

Duration: Bond Sensitivity to Rates

Duration measures how sensitive a bond is to interest rate changes.

Example:

• Short-duration bond (2-year maturity): Falls 2% if rates rise 1%
• Long-duration bond (30-year maturity): Falls 15-20% if rates rise 1%

Longer-term bonds are riskier in rising-rate environments (more price decline).

Bonds and Portfolio Risk

Bonds reduce portfolio volatility because they're negatively correlated with stocks:

Stock market crashes (bad for stocks):

• Economic weakness likely → rates fall
• Falling rates mean bond prices rise
• Bonds offset stock losses

Stock market booms (good for stocks):

• Economic strength likely → rates rise
• Rising rates mean bond prices fall
• Bonds provide modest drag

A 60/40 stock/bond portfolio is much less volatile than 100% stocks, even though returns are slightly lower.

Default Risk

Government bonds: Nearly zero default risk (governments can print money)

Investment-grade corporate bonds: Low default risk (<1% annually)

High-yield bonds: Significant default risk (3-5% annually)

During recessions, corporate bond defaults rise. A 6% high-yield bond is less attractive if it has a 5% default risk.

Credit Ratings

Credit rating agencies (S&P, Moody's, Fitch) rate bond safety:

AAA: Highest quality (Apple, Microsoft, U.S. government) AA: Very high quality A: High quality BBB: Investment grade (still safe) BB and below: Speculative (high-yield junk bonds)

Ratings affect yields: AAA bonds pay 3-4%; BB bonds pay 8-10%.

Bond Fund vs. Individual Bonds

Individual bonds:

• You know exactly what you'll receive at maturity
• Can hold to maturity, avoiding price risk
• Requires management (picking which bonds to buy)
• Minimum usually $1,000-5,000 per bond

Bond funds/ETFs:

• Professional management
• Diversification across many bonds
• Can liquidate anytime (but prices fluctuate)
• Low investment minimums ($1 for ETFs)
• Pay ongoing fees (0.03-1.00%)

Most individual investors should use bond ETFs for simplicity and diversification.

Historical Bond Returns

Historical bond returns have been roughly 4-5% annually, with much lower volatility than stocks (2-3% annual volatility vs. stocks' 15-18%).

Bonds' lower return is offset by lower risk. A diversified portfolio with stocks and bonds balances growth with stability.

Bonds in Current Environment

Bond yields change with interest rates:

Low-rate environment (2020): Bonds yielding 0.5-2%

High-rate environment (2024): Bonds yielding 4-5%

When rates are high, bonds become attractive. When rates are near zero, bond yields are unattractive.

The Bottom Line

Bonds are lower-risk, lower-return investments that provide income and portfolio stability. Government bonds are safest; corporate bonds offer higher yields for taking on credit risk. Bonds are especially valuable in stock-heavy portfolios, where they provide stability and negatively correlate with stocks.

For most investors, diversified bond funds are the best approach to adding bond exposure.