Marks and Spencer Group PLC's (LSE:MKS) ongoing cybersecurity breach has knocked 15% off its share price, and investors are bracing for more details when the retailer reports full-year results on 21 May.
In an update to customers, M&S confirmed that some personal customer information had been compromised, although no passwords or payment data were exposed.
Citi analysts estimate the sales hit could reduce adjusted pre-tax profit for the 2026 financial year by around 2% for each week the disruption continues. That may not sound huge, but it adds up quickly if shopper confidence takes time to recover.
The best-case scenario, according to Citi, is a swift resolution and recovery of most lost profits through business interruption insurance.
That was the experience of MGM Resorts in the US, which recovered more than 100% of operating losses following a similar breach in 2023.
Even so, MGM faced about 45 million dollars in legal penalties and a sharp increase in capital spending to upgrade IT systems.
For M&S, the risks include potential fines, prolonged impact on sales and limits on insurance payouts. A quick fix could make most of the financial damage short-lived. The market will be watching closely on 21 May.
Mid-afternoon, the shares were up 2.5% at 354.1p.