Your 10 most-asked bond questions, answered

If you were asked to guess how much the global bonds market is worth… what would you put it at? A few hundred billion dollars? Well, according to Research and Markets they've estimated the overall size of the global bond market was at $143.15 trillion in 2025. And they predict it will grow to $168.85 trillion by 2031.¹

It's no wonder we field so many questions about bonds. So, what are bonds? How do bonds work? And what role should bonds play in your portfolio?

I put a panel of wealth relationship managers (who offer 1-to-1 guidance to anyone who invests over £250k with us - which includes their pension) and advisers to the test. Here are their answers to customers’ 10 most-asked questions about bonds.

Read on or jump to the relevant question below.

1. What are bonds?
2. What are the different types of bonds?
3. How do bonds work?
4. What is the maturity of a bond and why does it matter?
5. Do all bonds carry the same risk rating?
6. Why should I hold bonds in my portfolio?
7. How can I tell what my portfolio’s exposure to bonds is?
8. How do interest rates affect bonds?  
9. What’s the outlook for bonds in 2025? 
10. How can I invest in a bond fund? 

1. What are bonds?

Think of a bond as an IOU. When you buy a bond, you’re effectively loaning money to an organisation for a certain length of time. It’s a debt-based investment. At the end of the agreed fixed period, the bond will mature and repay the initial capital. In addition, along the way the borrower will pay interest to you. 

2. What are the different types of bonds? 

There are a number of variations, but the following are the largest categories.  

Corporate bonds are issued by individual companies to finance their activities and investments.  

Government bonds (also known as gilts in the UK or Treasuries in America) are issued by countries to fund public spending

3. How do bonds work?

To help you understand how bonds work, it’s important to understand what price, coupon, yield and value all mean.  

The price is pretty self-explanatory. It’s what it costs you to buy the bond. The price of the bond will rise and fall over its ‘lifetime.’ It’s affected by all sorts of factors, including supply and demand, how close the bond is to maturity and credit quality as well as more macro influences like inflation, taxes and wages. Critically, bond prices are affected by interest rates. When interest rates increase, bond prices come down and vice versa. A bit like a seesaw.  

The coupon is what the borrower pays you while you own the bond. It doesn't go up and down which is why bonds are referred to as a fixed-income asset class.

A bond’s yield changes over time because it reflects the relationship between its fixed coupon and changing market price. This income is paid out at intervals, for example quarterly or annually.  

The value of the bond is what you’ll receive when you sell it. If you sell it at maturity, you’ll get the same amount that you paid for it (the borrower is simply settling its IOU). If you want to sell the bond before it matures, its value (the price someone else will pay for it) is worked out by a mix of the value of the debt to be repaid, the interest it pays each year, the number of years until maturity and how risky the debt is.  

4. What is the maturity of a bond and why does it matter?

Some bonds are short-dated and mature within five years, typically one to three years. As these carry less inflation and default risk, they usually receive lower interest (or yield/income). And some are long-dated bonds, more often used by governments, and mature upwards of ten years. These tend to receive higher interest. 

Of course, there are no guarantees and sometimes the interest on short-dated bonds can be higher than on longer-dated bonds. This tends to happen when central banks are increasing interest rates aggressively and can be an indication of an economic slowdown or recession ahead. This situation is known as an ‘inverted yield curve’.

5. Do all bonds carry the same risk rating?

Generally speaking, bonds sit on the lower end of the risk/reward spectrum. However, not all bonds are the same. In fact, each bond carries its own bond rating. There are several global rating agencies which assess the credit worthiness of a company or government.  

To find a bond’s rating, go to the fund information page of the bond you’re interested in on our website. Click on the portfolio tab and scroll to the ‘Fixed income style’ section.

Important information - investors should note that the views expressed may no longer be current and may have already been acted upon. There is a risk that the issuers of bonds may not be able to repay the money they have borrowed or make interest payments. When interest rates rise, bonds may fall in value. Rising interest rates may cause the value of your investment to fall. Due to the greater possibility of default an investment in a corporate bond is generally less secure than an investment in government bonds. Sub-investment grade bonds are considered riskier bonds. They have an increased risk of default which could affect both income and the capital value of the fund investing in them. Overseas investments will be affected by movements in currency exchange rates. Investments in emerging markets can be more volatile than other more developed markets. Select 50 is not a personal recommendation to buy or sell a fund. This information is not a personal recommendation for any particular investment. If you are unsure about the suitability of an investment you should speak to one of Fidelity’s advisers or an authorised financial adviser of your choice.