Financial Mathematics — Calculation of YTM
(Bonds — Valuation, Yield & Duration!)
Banks hold crores in bonds. Understanding bond valuation, YTM, current yield, and duration is critical for treasury and the JAIIB exam. This chapter covers all bond mathematics.
Banky Enters the Bond Market! 📊💰
The bank holds ₹500 crore in bonds. When rates rise, prices FALL — crores lost! Banky needs to understand WHY and HOW.
Bonds — Everything You Need
📖 Part 1 — What is a Bond? Key Terms + Types
Bond = Debt instrument. Issuer pays fixed interest (coupon) periodically + returns principal at maturity. Bonds are NOT part of net worth — they are DEBT! Interest is TAX DEDUCTIBLE (tax shield).
6 Terms: Face/Par Value (₹100/₹1,000), Coupon Rate (fixed %), Maturity (when returned), Redemption Value (amount at maturity), Market Value (trading price), Day Count (Actual/365, 30/360 etc.).
Types: Fixed rate, Floating (FRN), Zero-coupon (no interest, issued at discount), Junk/High-yield (below investment grade), Convertible (exchange for equity), Inflation-indexed, Perpetual (no maturity), Govt/Treasury (risk-free), Callable (issuer repays early), Putable (holder forces early repayment), Bearer (no named holder).
📊 Part 2 — Bond Valuation + 3 Key Rules
I = coupon, F = face value, kd = required return, n = years. Example: ₹1,000 par, 12% coupon, 3 yrs, 10% required → 120(2.487) + 1,000(0.751) = ₹1,049 → PREMIUM (coupon > market rate).
Semi-annual: Coupon ÷ 2, kd ÷ 2, n × 2. Value slightly higher (reinvestment advantage).
3 Rules: (1) Coupon > Market → PREMIUM. (2) Coupon < Market → DISCOUNT. (3) Coupon = Market → PAR VALUE.
💰 Part 3 — Current Yield, YTM, Duration
YTM includes coupon + capital gain/loss. Found by trial & error. At discount → YTM > coupon. At premium → YTM < coupon. At par → YTM = coupon.
Properties: Duration ≤ maturity. Zero-coupon: Duration = Maturity. Higher coupon → shorter duration. Longer maturity → longer duration. Higher YTM → shorter duration.
Exam-Ready Points
🎯 Must Remember!
- Bond = DEBT, NOT net worth! Interest is tax-deductible. “Bonds are part of net worth” = WRONG!
- Coupon > Market → Premium. Coupon < Market → Discount. Equal → Par.
- Price ↔ Rate: INVERSE. Rate ↑ = Price ↓.
- Current Yield = Coupon ÷ Price. Simple. Ignores capital gain/loss.
- YTM = Total return held to maturity. Most complete measure.
- Duration = Holding period where interest rate risk disappears.
- Zero-coupon: Duration = Maturity exactly. No periodic interest. Issued at discount.
- Higher coupon → shorter duration. Longer maturity → longer duration.
- Callable + Putable: Bonds can have BOTH options!
- Perpetual bond value = Coupon ÷ Required Return.
📝 Past Exam Questions
Last-Minute Flash Cards
⚡ Module C • Chapter 4 (Unit 22) Done!
- Bond = DEBT, NOT net worth. Interest tax-deductible. Bondholder = creditor.
- Value: I×PVIFA + F×PVIF. Coupon>Market→Premium. Equal→Par. Coupon
- Price ↔ Rate: INVERSE seesaw. Rate↑ → Price↓.
- Current Yield: Coupon÷Price (simple). YTM: Total return to maturity (complete).
- Duration: Rate risk vanishes. Zero-coupon=Maturity. ≤Maturity always.
- Types: Fixed, Float, Zero, Junk, Convert, Call, Put, Perpetual, Govt, Bearer.
Banky says: “Bonds=debt! Price↔Rate=seesaw! YTM=total return! Duration=magic point! Now I understand treasury!” 🎉📊
Next: Chapter 23 — Forex Arithmetic! 💪🌍