S4 Capital, the advertising company led by Sir Martin Sorrell, has revised down its revenue forecast for the year amid ongoing macroeconomic uncertainty and shifting client priorities. The firm now anticipates a like-for-like revenue decline in the high single digits, a larger decrease than the previously projected low single-digit fall.

Sorrell, executive chairman of S4 Capital, attributed the weaker outlook to a fragile economic environment compounded by rising geopolitical tensions. According to him, clients remain cautious, with major technology companies and hyperscalers increasingly directing capital expenditures toward expanding artificial intelligence (AI) capabilities rather than maintaining or increasing marketing operating expenses.

The company reported that a growing share of technology sector spending is geared toward AI development, which has affected traditional advertising revenues. Analysts at Peel Hunt have adjusted their net revenue forecast for S4, lowering expectations by 5 percent for the following year and projecting an underlying revenue decline of 3 percent.

Despite the downward revision in revenue, S4 Capital's net debt stands at £76 million, which is lower than analysts had anticipated. Adjusted earnings before interest, taxes, and other items (EBITDA) are expected to reach £85 million for the full year, aligning with market consensus. The firm has also benefited from cost-cutting initiatives implemented in the latter half of 2025, including reductions in headcount. At the end of June, it employed just over 6,150 staff, known internally as "monks," S4’s operating brand.

In the third quarter, S4 Capital’s net revenue fell 7.3 percent on a like-for-like basis. The company’s financial update comes one day ahead of the third-quarter results from WPP, the FTSE 100 advertising conglomerate that Sorrell founded in 1985. WPP is expected by analysts to report a 3.2 percent decline in underlying revenue for the same period.

Sir Martin Sorrell established S4 Capital in 2018 following his departure from WPP amid allegations of misconduct, which he has denied. He left WPP under terms described as a “good leaver.” Sorrell’s goal with S4 was to build a digital advertising competitor to industry leaders such as WPP. However, the company has faced several profit warnings, and its shares have suffered a steep decline, falling approximately 95 percent from a peak in 2021. On the London stock exchange, shares recently closed down 19.3 percent at 43.75 pence.