UK Market Breakdown: Oil Tops $100, FTSE Slides, Week of 7 September 2026

Brent crude broke above $100 a barrel on Wednesday and London's blue-chip index went with it. The FTSE 100 closed 1.38% lower on 9 September, according to a session wrap from 24/7 Wall St, taking the index to what Tickmill's daily review called a six-week low and completing three straight losing sessions. It was the sharpest fall of the week so far, on a day when the DAX in Frankfurt dropped 1.6% and the CAC 40 in Paris shed close to 2%.

The trigger was not a London problem. Brent futures pushed past the $100 mark to $100.49 a barrel, up more than 2.5%, and traded as high as $100.85, after US forces destroyed five Iranian tankers and Tehran responded with missile strikes in Jordan. Iran-aligned Houthi forces also attacked several Saudi energy facilities, forcing a temporary halt to some operations, while the Strait of Hormuz remained largely blocked. WTI rose to $95.09, up about 2.3%.

For UK investors the read-across was immediate: dearer energy feeds inflation, and the Bank of England is now being discussed as a possible hiker rather than a cutter. Governor Andrew Bailey told the Treasury Committee on Tuesday that risks to inflation remain to the upside, and that the market curve pricing three rate rises over roughly the next year looked fair to him.

The FTSE 100

The index came into the week at 10,831.09 after Friday's close and then lost ground every session. Monday brought a fall of 8.96 points, or 0.1%, to 10,822.13. Tuesday was almost a carbon copy: down 10.47 points, again 0.1%, to 10,811.66, a level corroborated by Trading Economics at 10,812. Wednesday was where the damage was done, with the 1.38% drop erasing several times the previous two days' losses combined.

Leadership was narrow throughout. On Monday, energy was the only convincing bid in the market: BP and Shell each rose about 1% as Brent traded above $97, while consumer-facing sectors sagged, with personal care, drug and grocery down 0.8% and beverages down 1.6%. Reuters noted that gains in energy were the main thing limiting the decline.

Tuesday split the same way. Commodity-linked shares carried the index while pharmaceuticals, consumer names and banks dragged. AstraZeneca fell 1.3% and GSK dropped 2.5%, ending 41p lower at 1,796.50p. British American Tobacco slipped 0.7% and Rolls-Royce 0.5%, while Lloyds led the losses among the banks with a fall of 1.2%.

Wednesday's selling was broader. Declines swept banking, insurance and the industrial heavyweights, and only a short list of names finished in the black, with gains of between 0.6% and 1.7% for Computacenter, Centrica, BP, SSE, Severn Trent, Entain, Endeavour Mining, Associated British Foods and BT Group — a mix weighted towards utilities, energy and food rather than financials or cyclicals.

The FTSE 250 and mid caps

The domestic-facing mid caps were dragged along rather than leading. The FTSE 250 finished Friday at 24,584.71 and eased around 0.1% to 0.2% on Monday to roughly 24,540. It then fell 0.64% to 24,348.85 and edged lower again on Wednesday, leaving it lower across all three sessions like its larger sibling.

Monday's mid-cap moves were mostly stock-specific rather than macro. Hollywood Bowl was the biggest FTSE 250 faller, down 5.7%, while Ceres Power led the risers with a gain of 4.4%. XP Power added 3.7% and Spire Healthcare 3.2%. The oil trade showed up here too: Harbour Energy and Hunting both gained more than 2% as Brent traded above $97 following renewed US-Iran attacks around the Strait of Hormuz.

Smaller companies held up better than the main market at the start of the week. The AIM All-Share added 0.3% on Monday and the FTSE SmallCap was virtually unchanged, with SigmaRoc leading the AIM advance after a well-received set of interim results. Gear4music went the other way on Tuesday, with the shares falling as investors digested news of slower summer trading.

The week's biggest movers

Victrex was the standout. The Lancashire polymer maker upgraded its full-year guidance on Wednesday, now expecting underlying pre-tax profit for FY2026 of £45m to £47m against previous guidance of £42m to £44m, and the shares soared as much as 15%, reaching 1,004p and touching a 52-week high of 1,018p. Management pointed to momentum through the fourth quarter led by aerospace, value-added resellers and electronics, with Asia-Pacific particularly strong, and confirmed that its previously announced 10% headcount reduction is complete with initial benefits already showing. Victrex also appointed an interim chief financial officer.

Computacenter produced the week's most dramatic reversal. The Hatfield-based technology services group, a FTSE 100 constituent only since June, published first-half results on Tuesday showing revenue up 71.6% to £6.85bn and adjusted pre-tax profit up 87% to £152.4m. The shares jumped as much as 6.8% in early trading, then turned and finished as the index's biggest faller, down 435p at 5,165p.

Energean rose more than 5% on Wednesday, quoted at 832p against Tuesday's close of 791.5p and touching 845.5p intraday, after half-year results showed profit after tax up 45% to $160m. Energean reports in US dollars, and free cash flow rose 35% to $250m.

Antofagasta gained about 4.7% on Tuesday to close at 4,081p, outpacing the index, after three-month copper on the London Metal Exchange set a fresh record at roughly $14,617 a tonne. Glencore rose 4.05% on the same day, and Anglo American and Rio Tinto also advanced with the copper price.

Weir Group added 3.52% on Tuesday, helped both by the copper rally and by a newly announced contract to supply grinding rolls to China's Zijin Mining.

Smith & Nephew was among Tuesday's worst performers, closing 38p lower at 1,026p, with medical device makers weighing on the index generally — Convatec fell 5.40p to 221.40p on the same session. JD Sports Fashion also featured among the fallers, down 2.12p at 80.88p.

On Wednesday the selling spread to consumer and media names, with Auto Trader down about 4.5% and Burberry off 3.2%.

Company news in focus

The week's liveliest deal story was Gamma Communications. The FTSE 250 telecoms group has already agreed a recommended cash offer from private equity firm Epiris at 1,120p a share, valuing it at about £1.02bn — a 53% premium to the 732p close on 7 April 2026, when talks began — with completion expected in the first half of 2027. Over the weekend the Sunday Times reported that Dutch private equity firm Waterland was preparing a higher offer, under which it would buy Gamma and sell two divisions to UK telecoms channel business Giacom. Gamma's board has taken the view that the Epiris route carries lower execution risk. Under the City Code on Takeovers and Mergers, Waterland must announce a firm intention to bid or walk away by 17:00 BST on 18 September.

Aberdeen Group settled its boardroom question. The asset manager named Torbjörn Magnusson as a non-executive director and chair-designate with effect from 9 September, succeeding the outgoing Sir Douglas Flint once regulatory approvals are in place. Jonathan Asquith continues as interim chair until Magnusson takes over. Magnusson chaired Nordea Bank from 2019 to 2022 and was chief executive of Sampo for almost six years to 2025, and will be paid a fee of £475,000 a year. Aberdeen shares rose 1.8% on the day.

Broker opinion on Computacenter split sharply after Tuesday's numbers. Jefferies raised its price target to 6,500p from 5,300p, while Panmure kept a hold rating with a 4,080p target. Gross margin fell to 9.6% from 12.6%, largely because high-volume technology sourcing for hyperscale and neocloud customers adds invoiced revenue at slimmer percentage margins.

Index membership is also about to change hands. Under the FTSE UK Index Series quarterly review, easyJet and Ithaca Energy will join the FTSE 100, while Entain and Persimmon drop into the FTSE 250. The changes are implemented at the close on Friday 18 September and take effect from the start of trading on Monday 21 September.

Earnings and trading updates

Monday was the busiest reporting day. SigmaRoc posted interim revenue up 2.5% to £523.1m and underlying EBITDA up 11.3% to £131.2m, lifting the margin 200 basis points to 25.1%, with adjusted pre-tax profit of £75.1m against £67.4m. Alongside the numbers the building materials group agreed to buy Lithuanian lime and dolomite producer Akcinė Bendrovė "Dolomitas" for €110m on a debt and cash-free basis, plus €8m for certain non-core assets, with completion scheduled for the fourth quarter of 2026. The shares led the AIM risers, closing 10.5% higher at 141.8p.

Concurrent Technologies reported first-half revenue up 10% to £23.2m and pre-tax profit up 19% to £3.2m, with order intake up 110% to £46.9m and the Systems division profitable for the first time. The AIM-quoted embedded computing specialist said it expects full-year revenue to be materially ahead of market expectations and profit to be ahead.

Ashmore delivered a more awkward set of full-year figures for the twelve months to 30 June 2026. Attributable profit rose 27% to £103.3m, but performance fees collapsed to £1.4m from £10.2m a year earlier and adjusted EBITDA fell 32% to £35.7m.

Computacenter's interims on Tuesday were the largest by value. Gross invoiced income rose 57.6% to £8,927.5m, the interim dividend was lifted 14.8% to 27.1p, and full-year adjusted pre-tax profit guidance was set at no less than £380m against a company-compiled consensus of £340.9m.

Energean's half-year results on Wednesday carried the clearest operational story. Production fell 10% to 124 kboe/d and revenue dropped 8% to $743m after Israel ordered a 41-day suspension of output between 28 February and 9 April. Output has since recovered, averaging 135 kboe/d over the eight months to August, with August alone topping 180 kboe/d.

Macro and the Bank of England

Chancellor John Healey used his first major speech on Monday, at a manufacturing plant in Coventry, to commit to fiscal discipline and growth and to say he would build on his predecessor's work rebuilding UK credibility in international bond markets. Tax and spending decisions for the Budget were conspicuously absent, and the gilt market barely blinked: the two-year yield was up less than two basis points that morning and the ten-year up one, in line with moves elsewhere.

Bailey's Treasury Committee appearance on Tuesday mattered more. He said the near-complete closure of the Strait of Hormuz was pushing energy prices higher, that refined product prices posed upside inflation risks, and that the market curve contained "essentially a risk premium". He also pushed back on the idea that a rate rise is a question of when rather than if.

Gilts stayed uncomfortable. The ten-year yield held around 5.2% on Wednesday, close to a 19-year high, as investors priced in the possibility of further tightening. Markets are fully pricing a 25 basis point Bank rate increase by December followed by two more in 2027, though the 17 September Monetary Policy Committee meeting is widely expected to leave rates unchanged. UK natural gas prices climbed to their highest since late 2022.

Sterling found no benefit from high yields. GBP/USD traded around 1.3546 to 1.3562 on Wednesday, while GBP/EUR held near 1.1650 on Tuesday. Adding to the pressure, CME's FedWatch tool put the chance of a US rate rise in September at about 58%, up from roughly 44% a month earlier, after Friday's strong American payrolls report.

Still to come

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