IG Group shares plunge 26% after profit warning on revenue and margin pressure

The scale of the move matters more than the warning itself: a single-digit revenue and margin revision translating into a drop of this size suggests the market had priced IG as a resilient, cash-generative platform and is now repricing that assumption. That read-across is uncomfortable for listed retail-trading and brokerage peers, where revenue is tied to client activity and margins to marketing and compliance costs. Whether the pressure proves company-specific or sector-wide is the open question, and the next signal will be how competitors frame their own outlooks.