A convertible bond is debt that can convert into another security, usually the issuer's common shares, under stated price and ratio terms.
A convertible bond is a debt security that can be converted into another security, usually a stated number of the issuer’s common shares, under terms set in the offering documents. It combines bond cash flows and credit risk with an embedded equity conversion feature.
Convertible note often describes the same broad idea in note form, while convertible security is the wider category that can also include convertible preferred stock. The label alone does not establish who controls conversion, whether conversion is optional or mandatory, or whether the ratio is fixed.
For a conventional fixed-price convertible:
Assume a $1,000 convertible bond has a fixed $50 conversion price. Its initial conversion ratio is 20 shares per bond:
| Share price | Conversion value: 20 shares | Immediate conversion economically attractive? |
|---|---|---|
| $40 | $800 | Usually not if the bond can be retained or redeemed for more |
| $50 | $1,000 | At conversion-price parity before other factors |
| $60 | $1,200 | Potentially, but the bond’s market value and terms still matter |
| $80 | $1,600 | Compare conversion value with the bond price and remaining option value |
If the shares trade at $60 and the bond trades at $1,260, its conversion value is $1,200 and its dollar conversion premium is $60. Expressed as a percentage of conversion value, the premium is 5%:
The $1,260 bond price is not guaranteed. It can reflect debt value, option time value, accrued interest conventions, credit risk, call provisions, expected dividends, stock volatility, liquidity, and adjustment clauses. Conversion also ends the holder’s debt claim under ordinary physical-settlement terms; the investor then owns shares whose price can fall.
If 50,000 such bonds were fully converted at 20 shares each, the issuer would create 1 million shares before any anti-dilution adjustment. That share count is an input to dilution analysis, not proof that reported earnings per share will fall by a particular percentage; interest savings, taxes, earnings, and accounting rules also matter.
| Term | Meaning | What to verify |
|---|---|---|
| Conversion right | Right or requirement to exchange the bond | Who controls conversion and when |
| Conversion ratio | Shares received per bond | Initial ratio and adjustment clauses |
| Conversion price | Implied share price in the formula | Fixed, reset, or market-price-based formula |
| Conversion value | Share price multiplied by conversion ratio | Current price, ratio, settlement terms |
| Conversion premium | Bond price above conversion value | Whether clean or dirty price is used |
| Zero-coupon convertible | Convertible debt with no periodic coupon | Accretion, put/call dates, tax treatment |
| Security | Debt claim | Conversion feature | Main additional risk |
|---|---|---|---|
| Straight bond | Yes | No | Credit and interest-rate risk |
| Convertible bond or note | Yes until conversion or settlement | Usually common shares | Equity volatility and conversion terms |
| Convertible preferred stock | Preferred equity claim | Usually common shares | Dividend, ranking, and dilution risk |
| Contingent convertible bond | Debt-like instrument | Trigger-based conversion or write-down | Trigger, loss-absorption, regulatory terms |
Contingent Convertibles require separate analysis because a regulatory or capital trigger can determine conversion or principal loss.
An issuer may accept future dilution in exchange for a lower coupon than comparable straight debt might require. An investor may accept a lower coupon for potential share-price participation while retaining a debt claim before conversion. Neither tradeoff is automatically favorable: price, volatility, credit, call terms, dividends, dilution, and liquidity determine the economics.
Investor.gov’s convertible securities guide explains conventional fixed formulas, market-price-based formulas, and dilution risk. Use current issuer filings and offering documents for security-specific terms.
This page is educational only and is not individualized investment, legal, or tax advice.