FIRST: WHAT IS A GILT?
A gilt is an IOU issued by the UK government.
When the government needs to borrow, it sells these bonds to investors and promises interest payments before returning the money at an agreed date. Different gilts mature over different periods, from a few years to several decades.
The yield is the return an investor receives at the bond’s current market price. Bond prices and yields move in opposite directions: when investors sell gilts and their prices fall, the yield available to a new buyer rises.
On Wednesday, the yield on the benchmark 10-year gilt briefly reached 5.294%, according to Reuters. That was its highest level since August 2007 before it eased back.
WHY DID YIELDS RISE?
This was part of a global bond sell-off rather than an event isolated to Britain.
Renewed conflict in the Gulf pushed oil prices higher, increasing concern that expensive energy could feed inflation. When investors expect inflation to remain elevated — or think central banks may keep interest rates higher — they demand a better return for lending money over many years.
Government debt levels also matter. Investors look at how much a country needs to borrow and how convincing its tax and spending plans appear. Greater uncertainty generally means lenders demand a higher yield.
Prime Minister Andy Burnham told parliament that the government would stick to its fiscal rules. The 10-year yield eased after his comments, but remained at historically high levels.
HOW DOES THIS AFFECT THE GOVERNMENT?
Higher yields make new government borrowing more expensive. The effect builds over time as old debt matures and is replaced, but the direction is simple: more money spent servicing debt leaves less room for public services, tax cuts or new programmes.
Pantheon Macroeconomics estimated that higher interest costs had reduced the finance minister’s fiscal headroom from £23.6 billion at the Spring Statement to about £13 billion.
Its economists calculated that taxes would need to rise or annual spending fall by about £11 billion merely to restore the previous narrow buffer. That is an estimate, not a Budget announcement, but it explains why an apparently remote bond-market move immediately becomes a political problem.
The government’s first Budget under Burnham is scheduled for 28 October.
DOES A 10-YEAR GILT SET MY MORTGAGE RATE?
Not directly.
The Bank of England sets Bank Rate, which currently stands at 3.75%. Variable mortgage rates are closely influenced by it. Fixed mortgage pricing is also shaped by swap markets, expectations for future interest rates, competition between lenders and each bank’s own funding costs.
Gilt yields are part of the same wider interest-rate environment. If government and market borrowing costs keep rising, fixed mortgage deals can become more expensive even without an immediate Bank Rate increase.
Anyone approaching the end of a fixed deal does not need to panic because of one trading session. It is sensible to check options several months before the current rate expires, understand any early-repayment charge and compare the total cost rather than only the headline rate.
IS THERE ANY UPSIDE?
Higher market rates can improve returns available on some savings products and newly purchased annuities. They can also reduce the market value of existing bonds, meaning the same move helps some savers while hurting some investors.
The important point is that gilt yields are not a scoreboard for whether the economy is simply “winning” or “losing”. They are the price the market demands for long-term government borrowing — and when that price jumps, the Treasury, lenders and households eventually notice.
Sources: Reuters and the Bank of England.
