Latest data from industry expert Kantar Worldpanel saw sales at the chain slip 0.7% in the 12 weeks to 17 July, with both premium and low-price operators taking further chunks out of Tesco's customer base. And unlike many of its FTSE 100 colleagues, the supermarket can't rely on foreign shoppers to help it mitigate difficult conditions in the UK.
It's true that Tesco's overseas divisions have picked up the pace in recent months -- underlying sales ticked 3% higher during March-May, the fourth consecutive quarterly rise. But these far-flung territories only account for a fifth of total revenues.
Tesco currently changes hands on a P/E rating of 24.8 times for the year to February 2017, sailing well outside the benchmark of 10 times indicative of high-risk stocks. I reckon this is extremely poor value given the company's alarming growth outlook.
Like Tesco, clothing colossus Next(LSE: NXT) is also being battered by a backcloth of rising competition and the need for savage price cuts.
Competitive pressures have been a particular problem for the retailer's Next Directory catalogue division, which stole a march on the rest of the high street with the early embrace of e-commerce. But its rivals have invested heavily in this growth channel more recently, giving Next a run for its money.
And I expect revenues at Next -- which has already disappointed investors with profit warnings in recent months -- to struggle still further as a probable lurch into recession quells British shoppers' demand for new clothes, and drives footfall at cut-price operators like Primark and H&M.
I reckon Next is an unattractive stock selection at the present time, even in spite of a conventionally-decent forward P/E ratio of 12.4 times.
In a hole
The likelihood of prolonged oversupply in the oil market also makes me extremely bearish on BP(LSE: BP), in both the near term and beyond.
Crude values have received a fillip in recent days after news emerged that Saudi Arabia may be negotiating an output freeze with Russia.
But investors should treat this news with a pinch of salt. Previous rumours of a much-needed cap failed to transpire at the start of 2016. And record production from both countries during the summer suggests that Riyadh and Moscow may not be as keen on brokering a deal as recent manoeuvring suggests. With US producers also getting back to work, maintaining or gaining market share is critical.
Meanwhile, signs of stagnating global trade adds a further problem to the oil market's supply/demand picture. And in the long term, increasing decarbonisation initiatives in both developed and emerging economies cast a shadow over BP's earnings outlook, particularly given the firm's lack of investment in 'green' energy.
I reckon BP remains a perilous stock pick for long-term investors, and a huge P/E multiple of 32.8 times for 2016 cements my view that the fossil fuel leviathan is a poor investment.
Royston Wild has no position in any shares mentioned. The Motley Fool UK has recommended BP. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors.