What Is a Bond?
The whole idea in one sentence, then one worked example that makes it concrete.
A bond is a loan. When you buy one, you're lending money to a government or a company. In return, the borrower — called the issuer — promises to pay you interest along the way and return your money at a set date.
You give money today → you receive cash flows in the future. That's the entire foundation of bond investing.
A ₹1,000 example
Suppose a company issues a 5-year bond with these terms:
| Term | Value |
|---|---|
| Face value | ₹1,000 |
| Coupon rate | 8% |
| Maturity | 5 years |
| Coupon frequency | Annual |
An 8% coupon on ₹1,000 face value means:
So you receive ₹80 every year, and at the end of Year 5 you also get your ₹1,000 principal back. Laid out as cash flows:
| Year | Cash flow |
|---|---|
| 0 | −₹1,000 |
| 1 | +₹80 |
| 2 | +₹80 |
| 3 | +₹80 |
| 4 | +₹80 |
| 5 | +₹1,080 |
The −₹1,000 in Year 0 is what you pay to buy the bond. Everything after that is money coming back to you. Once you see a bond this way — as a simple list of dated payments — bond pricing stops being mysterious. It's just a question of what that list of future payments is worth today, which is exactly what the calculator computes.
Who issues bonds?
Three broad categories borrow this way:
- Governments — to fund spending and infrastructure.
- Companies — to fund expansion, acquisitions, or refinance existing debt.
- Banks and financial institutions — to raise capital or manage their balance sheet.
The borrower is the issuer. The person who buys the bond is the investor or bondholder.
Five words you need before anything else
1. Face value
The principal the bond repays at maturity — ₹1,000 in our example. Also called par value or redemption value. It's fixed at issuance and never changes.
2. Coupon rate
The contractual interest rate, applied to face value: 8% × ₹1,000 = ₹80 a year. Important to internalise early —
The coupon rate is not the same thing as your return. They're related but different, and conflating them is the most common beginner mistake in bonds.
3. Maturity
The date the issuer repays your principal. A 5-year bond issued today matures 5 years from now. Think of it as answering: when do I get my money back?
4. Bond price
What the bond actually costs in the market today — and this is where it gets interesting. A ₹1,000 face-value bond does not necessarily cost ₹1,000. It might trade at ₹950, at exactly ₹1,000, or at ₹1,080, depending on where market interest rates sit relative to this bond's coupon. We work through exactly why in the next article.
5. Yield
The return implied by what you actually paid, not by the coupon rate printed on the bond. If you buy our ₹1,000/8% bond for ₹900 instead of ₹1,000, you're still collecting ₹80 a year — but your return is higher than 8%, because you paid less than face value for the same payments.
Coupon ≠ Yield. Nearly everything else in fixed income builds on understanding why.
A bond isn't always worth its face value
Say your ₹1,000 bond pays ₹80 a year. Now imagine new bonds of similar risk start offering higher rates. Your 8% coupon looks less attractive by comparison, so investors will only pay you, say, ₹950 for it. The bond is trading at a discount.
Now imagine the opposite: market rates fall, and your 8% coupon starts looking generous next to what's newly available. Investors might pay ₹1,050 for the same bond. It's now trading at a premium.
This produces the single most important relationship in bond investing:
Interest rates fall → bond prices generally rise
There's a precise mathematical reason for this — covered fully in the next article — but the intuition is enough for now: a bond's fixed payments become more or less attractive as the going rate for money changes, and price is what adjusts to compensate.
A bond as a cash-flow machine
A useful mental picture: a bond is a machine that produces two kinds of output — coupon payments along the way, and one lump principal payment at the end. Bond valuation is simply the question of what that stream of future outputs is worth today.
Why would anyone buy a bond?
- Income — regular coupon payments provide predictable cash.
- Capital preservation — high-quality bonds can help protect capital, though no bond is risk-free.
- Diversification — bonds often behave differently from equities.
- Matching a future need — a bond's scheduled payments can be lined up against a known future expense.
Can you lose money on a bond?
Yes — this is worth addressing early, because it's a common misconception. A bond's market value can fall well before maturity, and even a bond held to maturity carries risks beyond simple non-payment:
- Credit / default risk — the issuer may fail to pay as promised.
- Interest-rate risk — prices generally fall when market yields rise.
- Reinvestment risk — coupons you receive may only be reinvestable at lower rates later.
- Liquidity risk — it can be hard to sell some bonds quickly at a fair price.
- Call risk — a callable bond may be redeemed by the issuer earlier than expected.
Each of these gets its own dedicated explanation later in this series, once you have the pricing and duration tools to understand why they matter.
One bond, three different numbers
Suppose you're shown: ₹1,000 face value, 8% coupon, ₹950 market price. Three numbers, three different meanings:
| Number | What it tells you |
|---|---|
| ₹1,000 | Principal scheduled for repayment |
| 8% | Contractual coupon rate |
| ₹950 | What the bond costs in the market right now |
Market price is not face value. Coupon rate is not yield. Keeping those two distinctions straight resolves most beginner confusion in this subject.
Try it yourself
Take that exact bond — ₹1,000 face value, 8% annual coupon, 5-year maturity, trading at ₹950 — and ask: what yield does that price imply?
Higher than the 8% coupon — because you're paying less than face value for the same ₹80-a-year payments, your effective return is better than the coupon alone suggests. That gap between coupon and yield is the subject of the next two articles.
Common beginner mistakes
The one thing to remember
A bond is a collection of future cash flows.
Coupon tells you the periodic payment. Face value tells you the principal. Maturity tells you when the principal is due. Price tells you what those future payments cost today. Yield tells you the return that price implies. Everything else in fixed income is built from these five ideas.