Shares in Dixons Carphone dropped 8.5 per cent in early trading after a broker issued a double downgrade on the stock.
Exane BNP Paribas moved the retailer to an "underperform" rating based on near-term caution on profit and cash forecast.
In the long term, the broker said it it has concerns about the FTSE 250 firm's mobile business.
"With consensus, sentiment and forecast too optimistic in the face of macro headwinds, positive catalysts are hard to find," the broker said.
The downgrade comes less than two months after the company celebrated record results in what it acknowledged was a challenging marketplace. In June, Dixons Carphone reported that pre-tax profit had risen above £500m for the first time ever, to £501m.
The company recently sold its Spanish business, disposing of The Phone House of Spain, Connected World Services Europe and Smarthouse in a €55m (£50m) deal with Global Dominion Access, a tech services company based in Bilbao.