Shares in Ocado Group PLC (LON:OCDO) plunged on Tuesday as it warned of margin pressure from rivals and failed to mention technology tie-ups.
The stock slumped 45p, or 14%, to 277p as Ocado reported "sustained and continuing" margin pressure and said it was unlikely to change soon.
Investors were also likely to have been dismayed by the lack of any update about long-awaited partnerships with overseas retailers to maximise the potential of its retail technology.
Hargreaves Lansdown equity analyst George Salmon said: "At present, despite providing a fantastic service and growing the top line strongly, Ocado makes relatively little money.
"This means more deals are needed in order to justify the shares’ lofty valuation.
"Steiner remains confident, but investors will be anxious to see if he can woo another partner, and indeed when.”
Still, Ocado reported higher sales and orders per week in the 12 weeks to August 7, with group gross sales rising 15.4% to £314mln.
Average orders rose nearly 19%, which Ocado described as its best volume performance in more than five years.
But average order size fell 3.4% to £107.94, suggesting that people were shopping more frequently but buying less on each shop.
Chief executive Tim Steiner said: "As the market remains very competitive, we are seeing sustained and continuing margin pressure and there is nothing to suggest this will change in the short term.
"We are confident our commitment to further improving the customer experience through constant innovation, supported by our world-class proprietary technology, will allow us to continue to grow ahead of the online grocery market, and substantially ahead of the market overall."
Andrew Wade at Numis Securities said: ". We leave our top-line estimates unchanged but, reflecting the price/margin pressure, edge down our full-year earnings before interest, tax, depreciation and amortisation (EBITDA) estimate."