CFA Level II Exam · Valuation and Analysis of Bonds with Embedded Options

Convertible Bond Valuation and Analysis for CFA Level II

Updated 7 October 2026 · Fact-checked

A convertible bond is a straight bond plus a call option on the issuer's shares, held by the investor. Its minimum value is the higher of conversion value and straight bond value. Compare the market price with conversion value to get the premium, then judge whether it behaves like debt or equity.

Understand Convertible Bonds: Valuation and Analysis

A convertible bond is a bond that the holder can exchange for a fixed number of the issuer's common shares. That number is the conversion ratio. Think of it as two pieces in one security: a straight (option-free) bond, plus a call option on the stock owned by the bondholder.

Because the investor owns the option, the investor pays for it. So convertibles usually offer a lower coupon and yield than a comparable straight bond from the same issuer. The investor gives up some income for the chance to share in share-price gains.

Conversion value is what you would get if you converted today: share price × conversion ratio. Straight value is the present value of the bond's cash flows at the yield of a comparable non-convertible bond. The convertible can never sensibly trade below the higher of these two, so that is its minimum value. Otherwise there would be an arbitrage.

Market price is normally above that floor, because the option still has time value. The gap shows up in the market conversion price and the market conversion premium. This is what you effectively pay per share when you buy the stock through the bond, compared with buying the stock directly.

The behaviour changes with the share price. A convertible is called busted when its conversion value is far below its straight value. It then trades like straight debt: its price follows the straight value and is driven by rates and credit. When the stock is high, the convertible is equity-like: its price follows conversion value. In between, it mixes both, and the downside is cushioned by the bond floor. Also remember the exam view of the option: the embedded call belongs to the investor, so it adds value to the bond, and the issuer may also have a call or the holder a put that you must account for.

Key formulas to remember

Conversion value: Conversion value = Market price of share × Conversion ratio; The value if converted now. Conversion ratio is the number of shares per bond.
Minimum value of a convertible: Minimum value = Max(Conversion value, Straight value); Market price should not stay below this level. Straight value is the PV of the bond's cash flows at a comparable straight-bond yield.
Convertible bond value: Convertible value = Straight value + Value of call option on the stock; Applies when there are no other embedded options. If the issuer can call, subtract the issuer call value; if the holder can put, add the put value.
Market conversion price: Market conversion price = Market price of convertible ÷ Conversion ratio; The effective price per share paid when buying the stock via the bond.
Market conversion premium per share: Premium per share = Market conversion price − Current market price of share; The extra amount paid per share compared with buying the stock directly.
Market conversion premium ratio: Premium ratio = Market conversion premium per share ÷ Current market price of share; Expressed as a percentage of the share price.
Premium over straight value: Premium over straight value = (Market price of convertible ÷ Straight value) − 1; A measure of downside risk: a low figure means the price sits close to the bond floor.
Favourable income differential per share: (Coupon interest per bond − Conversion ratio × Dividend per share) ÷ Conversion ratio; Income advantage of holding the bond over the stock, per share.
Premium payback period: Payback period = Market conversion premium per share ÷ Favourable income differential per share; Years of extra income needed to recover the premium. Ignores time value of money.

How to solve Convertible Bonds: Valuation and Analysis questions

Use the same order for any convertible question. Pull the data from the vignette first, then compute in a fixed sequence.

1Read the vignette and list: bond price, conversion ratio, share price, coupon, par value, dividend per share, straight-bond yield and any call or put features.
2Compute conversion value = share price × conversion ratio.
3Compute straight value as the PV of coupons and par at the comparable straight-bond yield, unless the vignette gives it.
4State the minimum value as the higher of the two and compare with the market price.
5Compute market conversion price = bond price ÷ conversion ratio, then the premium per share and premium ratio against the current share price.
6If asked about income, compute the favourable income differential per share and the payback period.
7Classify behaviour: share price far below the conversion price means debt-like; far above means equity-like. Then answer the risk-return question asked.
8Check units: per bond or per share, and whether the answer is a percentage or a currency amount.

Quickest way: Three-number shortcut: conversion value, market conversion price, premium

When to use it: Use it when the vignette gives bond price, conversion ratio and share price and the question asks about premium, minimum value or which side the bond trades on.

Multiply share price by conversion ratio. That is conversion value.
Divide bond price by conversion ratio. That is market conversion price.
Subtract share price from market conversion price. That is the premium per share. Divide by share price for the ratio.
Compare conversion value with straight value. The bigger one is the floor. If bond price is close to straight value, think debt-like; close to conversion value, think equity-like.
For payback, divide the premium by the income differential per share.

Common mistakes in Convertible Bonds: Valuation and Analysis

Using the bond's own yield instead of a comparable straight-bond yield to find straight value.
The convertible's coupon and yield are lower because of the option, so they understate the required return.
Fix: Discount at the yield of a similar non-convertible bond from the same issuer, as the vignette provides.
Treating the conversion value as the minimum value.
Students forget the bond floor when the stock price is low.
Fix: Always take the maximum of conversion value and straight value.
Forgetting dividends when computing the income differential.
Students compare only the coupon with zero.
Fix: Subtract conversion ratio × dividend per share from the coupon, then divide by the conversion ratio for the per-share figure.
Saying the issuer's call option adds value to the convertible.
Confusion over who owns each option.
Fix: Investor-owned options (conversion, put) add value. Issuer-owned options (call) reduce value.
Reading a low premium over straight value as a sign of equity-like behaviour.
Mixing up the two premium measures.
Fix: A low premium over straight value means the bond trades near its floor, so it is debt-like and the downside is limited. A low market conversion premium means the bond trades near its conversion value, so it is equity-like.

Worked examples

Example 1

A convertible bond has par value ₹1,000 (treat as the currency unit for the case) and trades at ₹1,150. The conversion ratio is 20 shares. The share price is ₹48. The straight value of the bond is ₹920. (a) Find conversion value and minimum value. (b) Find market conversion price and premium per share. (c) Find the premium ratio.

Show the solution

Conversion value = 48 × 20 = ₹960.
Straight value = ₹920. The higher is ₹960, so minimum value = ₹960. The market price of ₹1,150 is above it.
Market conversion price = 1,150 ÷ 20 = ₹57.50.
Premium per share = 57.50 − 48 = ₹9.50.
Premium ratio = 9.50 ÷ 48 = 0.1979, or 19.8%.

Answer: Conversion value ₹960; minimum value ₹960; market conversion price ₹57.50; premium per share ₹9.50; premium ratio about 19.8%.

Example 2

Using the same bond, the coupon is 3% on par ₹1,000, so ₹30 per year. The share pays a dividend of ₹0.50 per share a year. (a) Find the favourable income differential per share. (b) Find the premium payback period. (c) Find the premium over straight value.

Show the solution

Annual dividend on 20 shares = 20 × 0.50 = ₹10.
Income advantage per bond = 30 − 10 = ₹20. Per share = 20 ÷ 20 = ₹1.00.
Payback period = 9.50 ÷ 1.00 = 9.5 years.
Premium over straight value = 1,150 ÷ 920 − 1 = 1.25 − 1 = 0.25, so 25%.

Answer: Favourable income differential ₹1.00 per share; payback period 9.5 years; premium over straight value 25%.

Exam tips

Write the conversion ratio, share price and bond price at the top of your scratch work before any calculation. Most errors come from using the wrong input.
Check whether the vignette gives straight value directly. If it does, do not recompute it.
For risk-return questions, link the share price to behaviour: far below the conversion price means debt-like, far above means equity-like.
Check who owns each option. Conversion and put options add value, call options subtract it.
Level II questions are vignette-based, so pull the inputs from the vignette first. Compute the conversion value and compare it with the market price to eliminate answer options quickly.

Convertible Bonds: Valuation and Analysis in other exams

The same ground in other exams, if you are preparing for more than one or want another angle on it.

Convertible Bonds: Valuation and Analysis: frequently asked questions

How do you value a convertible bond for CFA Level II?

Value it as a straight bond plus a call option on the stock, adjusting for any issuer call or holder put. For exam questions you often only need the minimum value, which is the higher of conversion value and straight value, and then compare it with the market price.

What is the difference between conversion value and market conversion price?

Conversion value is the value of the shares you would receive today: share price × conversion ratio. Market conversion price is what you effectively pay per share through the bond: bond price ÷ conversion ratio.

Why does a convertible bond have a lower yield than a straight bond?

The investor owns an equity call option within the bond and pays for it by accepting lower coupon income. Compared with a straight bond from the same issuer, the convertible gives up yield in return for upside potential.

How does a convertible compare with a straight bond and with the stock in risk and return?

Compared with a straight bond, a convertible has more upside when the share price rises, but a lower yield. Compared with the stock, it has a bond floor that limits downside, but the premium means you pay more per share and you capture less of the early gains.