Which? cheapest supermarket of 2025 revealed

Which? found Aldi to be the UK’s cheapest supermarket for the fifth consecutive year, topping monthly price comparisons in 10 of 12 months; a 68-item basket cost £123.60 at Aldi in December versus £123.70 at Lidl. Other December basket prices: Asda £134.89; Tesco £135.84 with Clubcard (£139.12 without); Sainsbury’s £141.45 with Nectar (£143.74 without); Morrisons ~£140.03; Ocado £155.23; and Waitrose £170.46 — £46.86 more than Aldi, which could amount to over £1,000 annually if shopping every 2–3 weeks. The data highlights persistent cost-of-living pressures and reinforces the competitive advantage of discount grocers for price-sensitive households.

Analysis

Market structure: The data concretely reinforces a two-tier UK grocery market — discount (Aldi/Lidl, private) winning on price and mid/large chains (Tesco, Sainsbury’s, Morrisons) competing on loyalty and branded breadth. A £46.86 per-basket gap (Aldi £123.60 vs Waitrose £170.46) implies ~£1,000+/yr divergence for 24 shops, creating durable share shifts if frequency persists over 12–36 months. Listed winners are those with scale + loyalty monetisation (TSCO.L, SBRY.L); losers are higher-priced models and pure-play online (OCDO.L) and branded CPGs facing private-label displacement.

Risk assessment: Tail risks include a regulatory clampdown on rapid discount expansion or supplier-price squeeze, and a commodity shock (e.g., wheat/oil) that could compress margins unevenly across retailers. Time horizons: immediate (weeks) = volatility around monthly basket datasets and CPI; short (1–6 months) = Q1–Q2 retail earnings and loyalty program metrics; long (1–3 years) = structural market-share migration to discounters. Hidden dependencies: loyalty engagement rates, private-label supply contracts, and online fulfillment costs (critical for Ocado).

Trade implications: Tactical relative-value: favour large omnichannel grocers with sticky loyalty programs and supply-chain scale. Expect downside for Ocado-style valuation premia if price-conscious shoppers persist; disinflationary pressure in staples could modestly lower UK core CPI, helping gilts. Catalysts to act: next two Which?/Kantar basket releases, UK CPI prints, and Q1 retail results (3-month window).

Contrarian angles: Consensus underestimates loyalty-program leverage — Tesco/Sainsbury’s can defend margins via targeted offers and data monetisation, limiting long-term discounter share capture. Market may be overpricing structural damage to branded CPGs; historical parallels (2010s discounter rise in Europe) show incumbents retain ~60–80% of volumes with margin compression but not extinction. Unintended consequence: aggressive private-label scaling raises capex/working-capital needs for discounters, slowing expansion and creating entry points for listed grocers.

Key Decisions for Investors

• Establish a 2–3% long position in Tesco (TSCO.L) over 6–12 months — thesis: scale + Clubcard monetisation, target +15% total return if next two quarters show stable like-for-like sales and margin recovery; trim if YoY like-for-like sales miss by >2% or loyalty redemptions fall >10% quarter-on-quarter.
• Initiate a 1–2% short position in Ocado (OCDO.L) or buy 6‑month puts (10% OTM) sized equivalently — thesis: premium online pricing vs basket gap unsustainable; close if Ocado reports sequential GMV growth >8% QoQ or announces material margin-accretive partnership within 3 months.
• Pair trade: Long Sainsbury’s (SBRY.L) 1.5% / Short Morrisons (MRW.L) 1.5% for 3–9 months — conditional on Sainsbury’s Nectar uptake; exit if Sainsbury’s loyalty redemption rate drops >5ppt or Morrisons announces price investment program that narrows basket price gap by >£2 per basket in monthly reports.
• Allocate 1% to UK duration: buy 10y gilt futures if two consecutive UK CPI prints come in ≥0.2ppt below consensus (expect disinflation from grocery price competition), target 50–75bp rally in yields, stop-loss if CPI surprises >+0.3ppt.