Lecture 18: Bonds (Part 3)
Bonds and Interest Rate Sensitivity
Coupon Rates and Bond Pricing
Two bonds are compared:
- Bond A: 5% coupon rate
- Bond B: 10% coupon rate
Both bonds have a yield to maturity (YTM) of 8% and 5 years until maturity.
Price change is analyzed when YTM decreases from 8% to 7%.
Price Calculation Steps
Calculate price at YTM of 8% and 7% for both bonds.
Evaluate the percentage change in price between the two yield scenarios.
Semi-annual Cash Flows
For Bond A (5% coupon):
- Cash flows per $100 face value:
- $2.50 (every 6 months) + $100 (at maturity)
For Bond B (10% coupon):
- Cash flows per $100 face value:
- $5 (every 6 months) + $100 (at maturity)
Yield Adjustment
Yields are semi-annual rates:
- Current rate: 8% → 4%; future rate: 7% → 3.5%
Price Change Results
- Bond A (5% Coupon):
- Price increased from $87.83 to $91.68 → 4.4% increase
- Bond B (10% Coupon):
- Price increased from $108.11 to $112.47 → 4.0% increase
Interest Rate Sensitivity Insights
- Sensitivity to Interest Rate Changes
- The bond with lower coupon payments (5%) is more sensitive to interest rate changes:
- Smaller relative cash flows received earlier
- Later cash flows significantly affected by interest rate fluctuations.
Bond Pricing Dynamics
- Time Effects and Price Volatility
- Bond prices converge to face value (par value) over time.
- Unpredictable changes in yields can cause price fluctuations.
Corporate Bonds
Understanding Credit Risk
Government bonds seen as risk-free; corporate bonds inherit credit risk (default risk).
Higher default risk leads to higher coupon rates to entice buyers to invest.
Yield to Maturity (YTM)
Defaultable bond YTM does not equal the expected return.
Higher YTM does not guarantee higher expected returns.
Bond Ratings
Given by credit rating companies (e.g., DBRS, S&P, Moody's).
Ratings assess creditworthiness and risk of default.
Categories include investment-grade and speculative (junk) bonds.
Yield Curves
Constructed for corporate and provincial bonds, showing credit spread relative to risk-free government securities.
Example: Credit Spreads
Credit Spread Calculation
Firm guarantees a credit rating of AA; observe a 90 basis point spread for 5-year maturity.
Government bonds issuing at a 4.5% yield implies the firm's YTM is 5.4% (4.5% + 0.9%).
Price Calculation for Corporate Bonds
Cash flows are $5 per year ($2.50 semi-annually).
Using a 5.4% yield, compute price of bonds, which shows trade-offs with coupon vs. default risk leading to price gaps (e.g., $98.27 vs. $100 for government bonds).