The London Stock Exchange‘s FTSE 100 bond rout has pushed the UK’s 10-year gilt yield seven basis points higher to 5.45 per cent, as a sharp spike in oil prices triggered a sell-off across global markets. The immediate catalyst was a surge in crude prices following reports that the Trump administration had instructed the Pentagon to develop strike options against Iran, potentially ahead of the midterm elections.
Brent crude, the international benchmark, soared above $102 per barrel on those reports. The move rattled bond markets, with the 10-year gilt yield initially rising ten basis points before settling seven basis points higher at 5.45 per cent, adding to the government’s cost of borrowing.
Oil Surge Deepens the FTSE 100 Bond Rout
The scale of the move in energy markets was stark. According to The Hill, Brent crude climbed to $104.60 per barrel on Thursday morning, a jump of 4.4 per cent. West Texas Intermediate (WTI), the US benchmark, was not far behind, rising 3.91 per cent to settle at $92.19 per barrel.
Those are substantial single-session moves for oil markets, and they fed directly into the bond sell-off that has weighed on equities. When energy prices rise sharply, inflation expectations tend to follow, and investors demand higher yields to hold government debt. That dynamic played out in the gilt market, tightening conditions for UK borrowers, both public and private.
The FTSE 100 returned to negative territory as the combination of higher borrowing costs and geopolitical anxiety pressed on equities across London and the wider global market. UK businesses with significant interest-rate exposure or dollar-denominated commodity costs faced the sharpest headwinds.
Iran Tensions Drive the Geopolitical Risk Premium
Underpinning the oil move is a deteriorating picture in the Gulf. The National reports that Iranian attacks on oil and gas tankers in the Strait of Hormuz have climbed to their highest weekly rate since the conflict began on 28 February. The Strait of Hormuz is the passage through which a large share of the world’s seaborne oil moves, and any sustained disruption there is felt almost immediately in crude pricing.
The reports of US planning for potential military action against Iran added a further layer of uncertainty. Markets are pricing in the possibility, even if not the certainty, of supply disruption at a moment when the geopolitical backdrop in the Middle East is already stretched. That combination of an active tanker-attack campaign and the prospect of a broader escalation has given energy traders reason to push prices higher.
For UK businesses, the consequences reach beyond the fuel pump. Sustained high oil prices feed through into transport, logistics and manufacturing costs over a period of weeks and months. Combined with gilt yields at 5.45 per cent, companies refinancing debt or drawing on variable-rate facilities face a more expensive environment than they did only days ago.
The gilt market’s reaction also carries implications for the government’s finances. A sustained rise in borrowing costs limits the headroom available to the Treasury, at a moment when public spending pressures remain considerable. Even a seven-basis-point move, sustained over time, compounds into a material increase in debt-servicing costs across the stock of government borrowing.
The wider market picture reflects how quickly geopolitical news can translate into financial conditions for ordinary businesses. A reported planning exercise in Washington over a potential military action in the Gulf drove oil above $104 per barrel, pushed gilt yields to 5.45 per cent, and sent the FTSE 100 back into the red, all within a single trading session. The next move will depend on whether the reports of US strike planning are confirmed or contradicted by official statements from the Pentagon or the White House.
