S4, which the world's best-known ad-man set up after an acrimonious departure from WPP, boomed at first.
Lately it has faced accounting issues and has now cut sales forecasts for the second time in three months.
The shares crashed 25% to 71p leaving the company valued at £415 million. The stock was 245p at the start of the year.
S4 has cut staff numbers at its Media Monks arm from 9000 to 8550 and warned that it "continues to take action" on jobs, "given the current market outlook". Staff in the content part of the company are especially vulnerable.
WPP shares were also hit, down 2% at 757p. Brokers at Peel Hunt cut their rating on Soho ad firm M&C Saatchi.
Denne historien er fra September 18, 2023-utgaven av Evening Standard.
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Denne historien er fra September 18, 2023-utgaven av Evening Standard.
Start din 7-dagers gratis prøveperiode på Magzter GOLD for å få tilgang til tusenvis av utvalgte premiumhistorier og 9000+ magasiner og aviser.
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