Interest Rates & Yield Curves

Interest rates are among the most important factors affecting securities prices. Investment advisers must understand how rates work, how they're set, and what the yield curve reveals about economic expectations.

What Are Interest Rates?

An interest rate is the cost of borrowing money, expressed as a percentage of the principal. It's also the return earned by lenders for providing funds.


Key Interest Rates

RateWhat It IsSet ByCurrent Typical Level
Federal Funds RateRate banks charge each other overnightFederal Reserve (target)4-5% range (2025)
Prime RateRate banks charge their best customersBanks (typically fed funds + 3%)~8%
Discount RateRate Fed charges banks for direct loansFederal ReserveAbove fed funds
SOFRSecured Overnight Financing Rate (replaced LIBOR)Market-determinedTracks fed funds closely
Treasury RatesYields on U.S. government securitiesMarket forcesVaries by maturity

The Federal Funds Rate

The federal funds rate is the benchmark for short-term rates in the economy:

  1. Fed sets a target range (e.g., 5.25%-5.50%)
  2. Prime rate typically = Fed funds + 3%
  3. Other consumer rates adjust accordingly
  4. Eventually affects mortgages, auto loans, credit cards, business loans

Interest Rates and Bond Prices: The Inverse Relationship

This is one of the most important relationships in finance—and a favorite topic on securities exams:

Bond prices and interest rates move in opposite directions.

Why the Inverse Relationship?

When Rates RiseWhen Rates Fall
New bonds issued with higher couponsNew bonds issued with lower coupons
Existing bonds (lower coupons) less attractiveExisting bonds (higher coupons) more attractive
Existing bond prices fallExisting bond prices rise

Example

You own a bond paying 4% interest. Market rates rise to 5%:

  • Who would pay full price for your 4% bond when they can buy a new 5% bond?
  • Your bond's price must fall until its yield matches current market rates

Conversely, if rates fall to 3%:

  • Your 4% bond is now more attractive than new bonds
  • Your bond's price rises

Duration: Measuring Interest Rate Sensitivity

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

DurationRate SensitivityExample
Short (1-3 years)Less sensitiveMoney market funds, short-term bonds
Intermediate (4-7 years)ModerateMedium-term bond funds
Long (10+ years)Most sensitiveLong-term Treasury bonds

Rule of Thumb

For every 1% change in interest rates, a bond's price changes approximately equal to its duration:

Bond Duration1% Rate Increase1% Rate Decrease
3-year~3% price decline~3% price increase
10-year~10% price decline~10% price increase
20-year~20% price decline~20% price increase

Investment Implication: When expecting rates to rise, shorten duration. When expecting rates to fall, extend duration to capture price appreciation.


The Yield Curve

The yield curve plots interest rates of bonds (typically Treasury securities) across different maturities. It provides crucial insights into economic expectations.

Types of Yield Curves

ShapeDescriptionWhat It Signals
Normal (Upward-Sloping)Long-term rates > short-term ratesEconomic expansion expected; investors demand premium for longer commitments
FlatRates similar across maturitiesUncertainty or transition; economy may be changing direction
Inverted (Downward-Sloping)Short-term rates > long-term ratesPotential recession ahead; historically reliable predictor
HumpedIntermediate rates highestMixed signals; less common

Why the Yield Curve Predicts Recessions

An inverted yield curve has preceded every U.S. recession since 1970:

  1. Investors expect the Fed to cut rates in the future due to economic weakness
  2. They lock in current long-term rates before they fall
  3. This demand for long-term bonds pushes long-term rates down
  4. Short-term rates remain high due to current Fed policy
  5. Result: short-term rates exceed long-term rates (inversion)

The Federal Reserve Bank of New York uses the yield curve slope to calculate recession probability.


Credit Spreads

Credit spread = Yield on corporate bond − Yield on Treasury bond of same maturity

Spread BehaviorWhat It Signals
Widening spreadsGrowing credit concerns; investors demanding more compensation for risk
Narrowing spreadsImproving confidence; risk appetite increasing
High-yield (junk) bondsWidest spreads; most sensitive to economic conditions

Economic Signal: Widening credit spreads often precede or accompany recessions as investors become more risk-averse.


Impact on Different Investments

Bonds

Rate ChangeBond Price EffectDuration Effect
Rates rise 1%Prices fallLonger duration = larger decline
Rates fall 1%Prices riseLonger duration = larger gain

Stocks

Higher interest rates typically hurt stocks through multiple channels:

ChannelEffect
Borrowing costsHigher costs for companies → lower profits
Consumer spendingHigher mortgage/loan payments → less spending
ValuationsFuture earnings worth less (higher discount rate)
CompetitionBonds become more attractive vs. stocks

Sector Sensitivity

SectorRate SensitivityExplanation
UtilitiesHigh (negative)High debt levels; dividend stocks compete with bonds
Real Estate/REITsHigh (negative)Higher financing costs; compete with bonds for yield
FinancialsComplexMay benefit from wider lending margins, but loan losses may rise
TechnologyHigh (negative)Future earnings heavily discounted at higher rates
Consumer StaplesLowDefensive; less affected by rate changes

In Practice: How Investment Advisers Apply This

When rates are rising:

  • Review client bond portfolios for excessive duration
  • Consider shorter-duration bonds or floating-rate securities
  • Evaluate rate-sensitive equity sectors for potential underweights
  • Discuss with clients that "safety" of long-term bonds includes interest rate risk

When rates are falling:

  • Consider extending duration to capture price appreciation
  • Look for opportunities in rate-sensitive sectors
  • Recognize that rate cuts often signal economic concerns
  • Consider refinancing recommendations for client debt

Yield curve monitoring:

  • Watch for yield curve inversion as recession warning
  • Steepening curve (long rates rising faster) may signal inflation concerns
  • Flattening curve may signal slowing growth expectations

On the Exam

The Series 65 exam frequently tests:

  1. Inverse relationship between interest rates and bond prices
  2. Duration as a measure of interest rate sensitivity
  3. Yield curve shapes and their economic implications
  4. Inverted yield curve as recession predictor
  5. Credit spreads and what they indicate

Expect 2-3 questions on interest rates. A common question format is: "When interest rates rise, bond prices..."


Key Takeaways

  • Bond prices move inversely to interest rates—this is fundamental
  • Duration measures interest rate sensitivity; longer duration = greater sensitivity
  • Normal yield curve: long-term rates > short-term rates (expansion expected)
  • Inverted yield curve: short-term rates > long-term rates (recession warning)
  • Inverted yield curves have predicted every recession since 1970
  • Credit spreads widen during economic stress
  • Rising rates generally hurt both bonds (directly) and stocks (through valuation and cost effects)
  • Investment advisers should monitor the yield curve as an economic indicator
Test Your Knowledge

When interest rates rise, what typically happens to existing bond prices?

A
B
C
D
Test Your Knowledge

An inverted yield curve, where short-term rates exceed long-term rates, is considered a signal of:

A
B
C
D
Test Your Knowledge

Which bond would experience the LARGEST price decline if interest rates rose by 1%?

A
B
C
D