Yield Measures and Total Return: NISM Series XXII Comprehensive Guide (Part 1)

In the fixed income market, an investor who parts with their money essentially postpones present consumption for a future date. Because the future value of consumption is likely to be impacted by expected inflation and the investor takes on counterparty risk, they expect a return commensurate with this opportunity loss and risk. The returns on these debt investments, when expressed as an annualized percentage, are referred to as the yield or interest rate. These standardized measures allow for the effective comparison of different investment alternatives.

5.1 Understanding the Primary Sources of Return

Fixed income investors benefit from three main components of return during the life of a bond: periodic coupon payments, capital gains or losses from price movements, and reinvestment income from received cash flows.

5.1.1 Coupon Income

Coupon income is the regular, promised flow of money from the borrower to the lender as specified in the bond's indenture.

• Fixed Coupons: Most traditional bonds, such as Government Securities (G-Secs), pay a fixed annual interest rate. For example, a "7% GS 2027" indicates an annual coupon of Rs 7 on a face value of Rs 100. In India, these are typically paid semi-annually, meaning the investor receives Rs 3.50 every six months.
• Zero-Coupon Bonds: These instruments do not pay any periodic interest; instead, the investor receives the face value (e.g., Rs 100) at the end of the investment period.
• Floating Rate Bonds: These provide varying coupons based on a benchmark, such as the 182-day Treasury Bill rate in India.

5.1.2 Capital Appreciation and Depreciation

The market value of a bond changes continuously as interest rates fluctuate. If an investor sells a bond before its maturity date, they may experience capital appreciation or depreciation.

• Inverse Relationship: The fundamental rule of bond pricing is that when market interest rates fall, bond prices rise (appreciation), and when market interest rates rise, bond prices fall (depreciation).
• Yield vs. Coupon: Coupons are set at issuance based on prevailing rates. If current market rates for similar bonds drop below the promised coupon, the old bond becomes more valuable and trades at a premium (above Rs 100).
• Term Premium: Long-term bonds typically pay a term premium, which is the extra yield investors demand for the uncertainty of lending over longer horizons. This is often measured as the spread between a 10-year yield and a 3-month yield.

5.1.3 Reinvestment Income

Investors receive periodic coupons which can then be reinvested into other assets to yield further income. This is effectively "interest on interest". The standard Yield to Maturity (YTM) calculation assumes that all future coupons are reinvested at the same YTM rate throughout the bond's life.

5.2 Traditional Yield Measures and Market Conventions

Because bonds can have different maturities, coupons, and credit ratings, their prices alone do not provide enough information for comparison. Yields provide a unified measure to determine if a bond is fairly valued.

5.2.1 Defining Yield and the Internal Rate of Return (IRR)

Yield is the interest rate that equates the present value (PV) of all known future cash flows to the bond's current market price.

The Bond Price Formula (Line Format): PV = sum of (Cn / (1 + r)^n) + (Redemption Value / (1 + r)^n).

In this equation, r represents the yield or the Internal Rate of Return (IRR). In Microsoft Excel, the PRICE function uses variables such as START_DATE, END_DATE, COUPON, YIELD, FACE_VALUE, FREQUENCY, and DAY_COUNT to compute these values.

5.2.2 Important Market Yield Classifications

The market typically explains yield in three distinct ways:

1. Yield to Maturity (YTM): The most common measure, assuming the bond is held to maturity and all coupons are reinvested at the same rate.
2. Spot Yield: Also known as the Zero-Coupon Yield, used for Treasury bills and STRIPS. It represents the yield for a specific maturity with no interim cash flows.
3. Forward Yield: An implied future yield derived from current spot yields, assuming no-arbitrage behavior.

5.2.3 Market Conventions and Accrued Interest

Bond pricing depends on specific market conventions regarding coupon frequency and day counts. In India, the FIMMDA handbook is the primary guide for these standards.

Accrued Interest (AI)

Bonds are traded at a Clean Price, but the buyer must pay the seller the Dirty Price (Clean Price + Accrued Interest) at settlement. Accrued interest compensates the seller for the portion of the coupon earned since the last payment date.

Accrued Interest Formula (Line Format): AI = Coupon * (Days from last coupon / Days between last coupon and next coupon).

Common Day Count Fractions

Different markets use various methods to calculate the "days" used in the accrued interest formula:

1. Actual/Actual: Uses the exact number of calendar days; useful for leap years.
2. 30/360E: Assumes every month has 30 days and the year has 360 days; widely used in the Indian government bond market.
3. Actual/360: Uses actual days but a 360-day year; common in swap valuations.
4. Actual/365: Uses actual days and a 365-day year; standard for the Indian money market.

Indian Bond Market Day Count Formula (Line Format): Day count Fraction = ([360 * (Y2 - Y1)] + [30 * (M2 - M1) + (D2 - D1)]) / 360.

5.2.4 Current Yield

The Current Yield is a simple measure used to compare the relative attractiveness of bonds for a single coupon cycle. It only considers coupon income and ignores capital gains/losses or the time value of money.

Current Yield Formula (Line Format): Current Yield = (Coupon / Clean Price) * 100.

Example: If the 7.17% GS 2028 is trading at a clean price of Rs 96.2290, its current yield is 7.45% [ = (7.17 / 96.2290) * 100 ].

[End of Part 1. Part 2 will cover Yield to Maturity (YTM) in detail, Effective Yield, Yield to Call/Put, and Yield measures for Money Market and Floating Rate instruments.]*