A convertible note is a debt security with terms that allow or require conversion into company equity under specified conditions. It begins as a borrowing obligation, not an ordinary purchase of common shares. Some notes settle conversions in shares; others permit or require cash, or a combination.
That distinction matters when you review a company's financing. A note can create a repayment obligation today and a possible increase in shares later. Neither outcome is fully described by a headline saying the company has raised money. Our balance-sheet basics guide explains the broader distinction between liabilities and equity.
The SEC's convertible-securities explanation covers the broader category, which can also include convertible preferred stock. This guide focuses on notes: the debt version, especially those disclosed by public companies.
Key Takeaways
- Convertible notes begin as debt with a conversion feature; they are not the same as common shares or employee stock options.
- Principal, interest, maturity, conversion conditions and settlement terms must be read together.
- A conversion price is part of a contract, not a stock-price target or a forecast.
- New shares issued on conversion can reduce an existing shareholder's percentage ownership; cash settlement changes that calculation.
- Company financing documents explain the note terms. A Form 4 reports a covered insider's ownership activity, not the entire financing arrangement.
How does a convertible note work?
A company receives financing and issues a note that specifies what it owes and how conversion can occur. The contract determines whether conversion is optional, mandatory after a trigger, or available only during certain periods.
Before conversion, the holder has rights under a debt instrument. Those rights differ from owning common stock. The SEC's corporate-bond overview explains the basic creditor-versus-shareholder distinction and the risk that a company fails to pay its obligations.
An issuer is simply the company issuing the security. For a public-company note, an indenture is the agreement setting out the debt terms. A summary announcement can introduce those terms, but the agreement and subsequent filings provide the detail.
| Term | Plain-language meaning | What to check |
|---|---|---|
| Principal | The face amount of debt. | Which amount can convert, and what must be repaid in cash? |
| Interest or coupon | The stated interest terms. | Is interest paid, accrued, or absent? Does it enter the conversion calculation? |
| Maturity | The contractual due date. | What happens if the note has not converted or been repurchased? |
| Conversion price or rate | The formula connecting debt to shares. | Is it fixed initially, adjustable, or linked to market prices? |
| Conversion conditions | Rules governing when conversion is available or required. | Who controls conversion, and what events or dates matter? |
| Settlement | How the conversion obligation is satisfied. | Shares, cash, or a specified combination? |
The last two rows prevent a common misreading: knowing a conversion rate does not establish that holders can convert immediately or receive that exact number of newly issued shares.
Do convertible notes always pay interest?
No. Interest terms vary. A note can have a stated coupon, while another has no regular interest payments. A zero stated coupon does not turn a borrowing into free equity or remove the repayment and conversion terms.
For a documented example, Zscaler's July 1, 2025 pricing announcement described 0.00% convertible senior notes due 2028. It stated that the notes would not bear regular interest and their principal would not accrete, meaning grow over time. This is an illustration of the terms announced then, not a statement about the notes' outstanding status today.
How do you calculate shares from a conversion price?
For a simplified, all-share conversion, divide the convertible amount by the applicable conversion price. Alternatively, multiply the note's principal units by its stated conversion rate. First verify which amounts and settlement method the actual contract uses.
The CFA Institute's 2026 convertible-bond discussion distinguishes conversion price from conversion ratio, the number of shares associated with conversion. These contractual measures are different from the stock's current trading price.
Consider a hypothetical company with $1,000,000 of notes and a fixed $20 conversion price. Assume the entire principal converts into newly issued common shares, with no interest added, adjustments, fees, fractional-share treatment or cash settlement:
$1,000,000 ÷ $20 = 50,000 new shares.
If the contract instead states 50 shares per $1,000 principal, the same result follows: 1,000 principal units multiplied by 50 shares equals 50,000 shares.
A stock trading above $20 would not, by itself, override a contractual conversion window or trigger requirement. Nor would the $20 conversion price establish what the stock is worth. It tells you how this simplified contract translates principal into shares, not whether the shares are attractively priced.
How can conversion dilute existing shareholders?
Issuing additional shares can reduce an existing shareholder's percentage ownership if that person's share count stays unchanged. Dilution describes that reduction; it does not, on its own, measure a stock-price loss.
Continue the hypothetical example. Assume the company has 1,000,000 common shares outstanding before conversion, and one shareholder owns 10,000. Ignore all other changes to the company or its capital structure.
| Measure | Before conversion | After the assumed all-share conversion |
|---|---|---|
| Total common shares | 1,000,000 | 1,050,000 |
| Existing shareholder's shares | 10,000 | 10,000 |
| Existing shareholder's ownership | 1.00% | Approximately 0.9524% |
The shareholder still has 10,000 shares, but the denominator is larger. The ownership reduction is about 0.0476 percentage points, or approximately 4.76% relative to the original ownership percentage. It is not a calculated 4.76% stock return.
This arithmetic deliberately leaves out the cash originally raised, changes in debt and the company's business performance. It isolates ownership mechanics. Our secondary-offerings explanation addresses another setting where issuing shares changes the ownership denominator.
Fixed and market-linked conversion formulas differ
With an unchanged fixed conversion price, the assumed convertible principal maps to a fixed share count. With a market-linked formula, the applicable price and resulting share count can change.
For example, the same hypothetical $1,000,000 convertible amount divided by $10 produces 100,000 shares, rather than 50,000 at $20. This is a sensitivity illustration, not a prediction that a particular note will reset to $10. The SEC's convertible-securities guidance explains why market-price-based formulas can create additional dilution risks.
Check for price floors, adjustments and other contractual limits before calculating potential issuance. A share-count estimate without those terms can be materially incomplete.
Why does cash settlement change the calculation?
Conversion does not necessarily mean exchanging the whole principal amount for new shares. A contract can require cash repayment of principal while permitting shares or cash for an additional conversion amount.
Exelon's December 1, 2025 pricing announcement illustrates this distinction. It described 3.25% convertible senior notes due March 15, 2029, with an initial conversion rate of 17.5093 shares per $1,000 principal, equivalent to an initial conversion price of approximately $57.11.
The announcement also specified cash settlement up to the converted principal amount. Only the remaining conversion obligation, if any, could be settled in cash, shares or both at Exelon's election. Early conversion was subject to conditions before a later conversion window.
Therefore, multiplying all announced principal by 17.5093 per $1,000 would not establish the number of new shares actually issued. The settlement clause matters as much as the headline rate. These are historical announced terms, not a claim that a conversion occurred or that the notes remain unchanged today.
Convertible notes, SAFEs and stock options are not interchangeable
The word “convertible” does not make every instrument debt. A SAFE, short for Simple Agreement for Future Equity, is a different financing agreement. The SEC's SAFE investor bulletin contrasts SAFEs with convertible notes, which generally represent a current company debt obligation.
Startup notes can tie conversion to a later financing or another triggering event. That structure differs from a public-company note with specified conversion windows and settlement provisions. A startup financing example should not be assumed to describe every listed company's notes.
| Instrument | What it represents | Important distinction |
|---|---|---|
| Convertible note | Debt with specified equity-conversion terms. | Repayment, conversion triggers and settlement provisions coexist. |
| Ordinary nonconvertible note | Debt without a contractual equity-conversion feature. | The principal does not become common shares under such a feature. |
| Common stock | An equity ownership interest. | It is not a promise to repay note principal. |
| Employee stock option | A contractual right to acquire shares at an exercise price under an award's terms. | It is not, by itself, a loan made to the company. |
| SAFE | An agreement for possible future equity under specified terms. | It is not interchangeable with a note's current debt obligation. |
Read each instrument's actual agreement. Familiar labels do not substitute for the rights attached to a particular security.
Where do convertible notes appear in SEC research?
Start with the company's financing disclosure and governing documents, then check later reports for changes. The amount announced, amount issued, amount outstanding and amount converted are different facts.
The SEC points to registration statements, annual and quarterly reports, and financing-related Form 8-K disclosures as places to research convertible arrangements. Our 10-K, 10-Q and 8-K guide explains those records. Search the debt footnotes and exhibits for the relevant note series, indenture and amendments.
If you also use Insider Trading Alerts, keep the company financing and the insider's reported transaction separate. A Form 4 is a public report of covered ownership activity, not the complete agreement governing the company's debt. Our 8-K versus Form 4 comparison explains that difference.
The SEC's Forms 3, 4 and 5 bulletin notes that reportable activity can involve derivative securities, including convertible securities. A reported conversion and a reported purchase are not interchangeable. Review the security title, code and footnotes rather than treating every share acquisition as the same event.
Insider Trade Alerts organizes eligible public Form 4 activity for research. An ownership alert can be a starting point for checking the original Form 4 fields; it does not establish the full financing's dilution or the issuer's ability to repay.
A short checklist for reading the terms
Before summarizing a convertible-note financing, identify:
- The note series, issuer and dates of the documents you are reading.
- Principal outstanding, interest terms and maturity, rather than only an offering's announced size.
- Who can initiate conversion and which conditions apply.
- The conversion formula, adjustments and any applicable floor.
- Whether settlement uses cash, shares or both.
- Later amendments, repayments, repurchases or conversions that change the original picture.
Debt terms do not guarantee payment. The corporate-bond guidance explains that creditworthiness and claim priority still matter, and that “senior” is not the same as “secured.” A conversion feature does not remove those risks or make a financing favorable or unfavorable by itself.
Educational information only, not investment, legal or tax advice. Public SEC filings are research records, not recommendations to buy, sell, hold or trade securities. Historical examples illustrate disclosed terms, not investment suitability or expected returns.
About the author: Chris Babayans writes about public SEC filings, market mechanics and research workflows for InsiderTradeAlerts. This guide uses primary regulatory material, issuer disclosures and CFA Institute educational material. Its arithmetic examples are hypothetical.