The busy week brought different fortunes for two retail partners as the market gave its seal of approval to Morrisons’ turnaround progress while hammering its online comrade Ocado.

Morrisons improved its second quarter like-for-like excluding fuel sales performance to 2% from 0.7% in the first quarter - its third consecutive quarter of like-for-like growth after a torrid period. That progress extended to the bottom line too, with first-half underlying operating profit up 11% to £207m after adjusting for last year’s restructuring costs and margin climbing back to 2.6%.

CEO Dave Potts understatedly declared himself “pleased”, but others were more animated. “We had pretty hefty expectations for Morrisons interims, and they were beaten across the board,” said Jefferies, noting as well its £1bn three-year cost savings target will be beaten and more savings have been identified for 2017/18 and beyond. “This is a strong set of results in the context of a continuing tough market backdrop and the strong volume growth implies Morrisons is still gaining traction with customers,” summarised UBS.

The grocer’s shares leapt 8.2% to 209.4p by lunchtime on Thursday - the first time the share had topped 200p since early April and representing an increase of over 40% so far in 2016. However, a note of caution was raised by Morgan Stanley: “Morrisons has clearly benefited from Asda’s big decline during the period. We expect Asda to invest in its customer proposition and the UK market and Morrison will continue to have to cope with numerous structural headwinds.”

Meanwhile, Ocado shares collapsed by more than 20% on Tuesday and Wednesday after warning of pressure on margins. The plunge came despite second-quarter results showing sales growth of 15.4% to £314m in the 12 weeks to 7 August. However, it was CEO Tim Steiner’s comments that Ocado faced “sustained and continuing margin pressure” that sent jitters through the market. Exane BNP Paribas concluded: “The core problem is in food retail online, gross profit is low and cost to serve high.” “The core problem is in food retail online, gross profit is low and cost to serve high. Ocado is probably the most successful at bringing down cost to serve but really, it’s just the least bad.”

Ocado has been subject to sporadic bid speculation which has helped its share price, but Exane is not convinced: “Amazon doesn’t typically buy businesses - it creates them. We doubt that Walmart will want much more exposure to the UK.”

Another company deep in the red this week was ABF, though this time it was its traditional growth-engine Primark under the microscope as its previously troubled sugar business recovers. A 30% rise in global sugar prices and increased revenue and profit from AB Sugar wasn’t enough to compensate for the first Primark like-for-like sales decline in 16 years and tightening margins. The shares collapsed 10.8% on Monday to 2,815p and remained 13.1% down for the week on Thursday at 2,740p.