The cost for Walmart of taking on Amazon was laid bare yesterday, when the world’s largest retailer lost nearly a 10th of its $200 billion (€175 billion) market value after warning that investment in ecommerce and wages would hit profits over the next few years.

Coupled with its earlier decision to raise hourly wages by $1 to $10 and spend more on training, the investment in ecommerce means Walmart expects earnings per share to fall between 6-12 per cent in the year starting next February. Consensus forecasts had been for 4 per cent growth.

It also cut its sales forecast for the current fiscal year. It expects no revenue growth this year compared with an earlier forecast of a 1-2 per cent increase. Walmart’s shares fell sharply, trading down by 10 per cent as the close approached in New York.