Why Primark’s owner fell 8% on a routine update

Most people who follow markets have a rough mental model: good news pushes shares up, bad news pushes them down. That model is not wrong, but it is incomplete. What actually moves a share price is the gap between what investors expected and what they got. This distinction is central to understanding the ABF trading update of 10 September 2026 — and to reading any company announcement confidently in the future.

ABF is one of Britain’s largest consumer goods companies. You might not recognise the name, but you almost certainly know its brands: Primark is ABF’s retail arm, and the food side includes Twinings, Ovaltine, Kingsmill, Silver Spoon, and Jordans, among others. The company trades on the FTSE 100 under the ticker ABF. As we explain in our post on what market capitalisation is, a company of ABF’s size — with a market cap well above £10 billion — has a large professional investor following. Those investors form precise views about what each update will contain. And it is those views, not the raw numbers, that determine where the share price goes on announcement day.

What the September trading update actually said

The September 2026 trading update covered ABF’s fourth financial quarter and gave a preview of the full year. According to the official announcement published on ABF’s investor relations page, the key headlines were:

• Group adjusted operating profit: expected to be broadly in line with previous market expectations.
• Adjusted earnings per share: expected to come in ahead of previous expectations — a positive, largely explained by lower interest costs.
• Grocery (Twinings and Ovaltine): adjusted operating profit expected to be slightly below previous expectations, due to short-term operational disruptions.
• Primark Q4 sales: total sales expected up around 2% year-on-year. However, new stores and franchise growth accounted for around 5 percentage points of that growth — meaning like-for-like (LFL) sales were expected to be down around 3%.
• Demerger: work on separating ABF’s Retail business (Primark) from its Food businesses is progressing, with completion targeted for December 2027.

On the surface, none of that looks catastrophic. Earnings per share ahead of expectations is a positive. Profits broadly in line is reassuring. Yet the shares still fell 7.9% on the day.

Understanding like-for-like sales

The most important number in the update — the one most likely to have moved the price — was Primark’s LFL sales figure of approximately minus 3%.

Like-for-like sales, often abbreviated to LFL or called “comparable sales”, measure growth in stores that were trading in both the current period and the same period a year ago. New store openings are excluded. This matters enormously for retailers, because it separates genuine demand growth from the effect of simply having more shops.

Primark has been expanding aggressively in recent years: new locations across Europe and the United States, plus a growing franchise model in markets where it does not own the stores directly. In Q4, all that expansion added about 5 percentage points to total sales growth. But strip that away, and the existing stores actually served 3% fewer sales than the year before. Customers were visiting, but spending less, or visiting less often.

A positive total sales figure driven entirely by new openings, combined with a negative LFL figure from the existing estate, is a pattern that concerns professional investors. It can suggest that consumer demand is softening faster than the expansion programme can compensate for. Analysts tracking Primark had been hoping to see an improvement in LFL momentum. The minus 3% figure was worse than many had expected.

Why “broadly in line” disappointed the market

The second issue was the overall profit outlook. “Broadly in line” is not bad news in isolation. It means the company is delivering what it previously promised. But professional investors track these companies continuously. In the weeks leading up to a trading update, they form views about whether the actual announcement will be a repeat of prior guidance, a confirmation, or an upgrade.

When a company upgrades its guidance — telling investors profits will be better than it previously said — the share price typically rises on the announcement. When guidance is simply reaffirmed, the share price tends to hold or drift slightly. When guidance is confirmed at a level lower than investors had hoped, it can trigger a sell-off, even if the number itself is not technically worse than what was said before. This is what happened with ABF. The market had priced in some probability of an upgrade, and “broadly in line” confirmed there would not be one.

Our post on what guidance means for shares explains this mechanism in more depth, and is worth reading alongside this one. The key principle is always the same: shares price in expectations, and they move on deviations from those expectations — not on the results themselves.

What is the demerger, and why does it matter?

The September update also included an update on something significant for ABF’s long-term structure: the planned demerger of Primark from the rest of the group.

A demerger means splitting a company into two separately listed entities. Instead of owning one ABF share that represents a slice of Primark, Silver Spoon, Twinings, and sugar operations all at once, shareholders would end up holding shares in two distinct companies — one focused entirely on Primark, and one covering the food divisions. ABF said in September 2026 that this demerger is expected to complete in December 2027.

Companies demerge for a specific reason: they believe the parts are worth more separately than they are together. The logic is about investor appeal. Someone investing in Primark wants exposure to fast-fashion retail: they want to track how consumer spending is holding up, how new markets are developing, and how the fashion cycle is playing out. They do not particularly want to own a stake in sugar production in southern Africa, or in the specialist yeast extract that goes into Marmite (another ABF brand). When these businesses sit inside the same company, neither gets the valuation it might deserve on its own.

This is a concept worth understanding for the challenge. When a demerger is announced, the individual businesses often re-rate — meaning their valuations change — because they attract different investor bases. The market’s reaction on the day depends on which direction that re-rating is expected to go, and whether the timing and costs of the split are seen as manageable.

Why the combination was enough to move the price

Taken alone, any one of the three issues in the ABF update might have had a muted effect. Profits broadly in line: fine. LFL down 3%: disappointing, but not a crisis. No change to demerger timeline: expected.

The combination, however, created a clearer picture for professional investors: the near-term trading environment for Primark was tougher than hoped, the food businesses were facing their own headwinds, and the company was not in a position to upgrade its outlook. That was enough to trigger a significant sell-off.

As we discuss in our post on why shares move on earnings news, it is rarely a single number that causes a large price move. More often, it is a combination of signals that push investors in the same direction at the same time. The 7.9% fall in ABF on 10 September was an illustration of that. Independent analysis from Hargreaves Lansdown noted that the soft LFL performance and limited near-term catalysts left little reason for investors to hold the shares at their previous level.

Three questions this event raises for challenge participants

If you hold a UK retailer or consumer staples company in your Student Investor Challenge portfolio, the ABF story offers a practical checklist for the next trading update you encounter:

1. Are LFL sales positive? Total sales can flatter a retailer that is simply opening more shops. LFL is the real underlying health check. If LFL is falling, ask whether it is temporary (a bad weather quarter, a competitor promotion) or structural (changing consumer habits, price sensitivity).
2. Is guidance being upgraded, maintained, or cut? The direction of guidance matters more than the level. An upgrade signals confidence about the future. A flat reaffirmation says the company is not willing to commit to better-than-expected performance. A cut is a clear warning.
3. What has the market already priced in? This is harder to judge without following analyst estimates closely, but you can get a rough sense from how the share has performed in the weeks before the update. A stock that has drifted higher heading into results has often priced in optimism. That optimism needs to be justified, or the price will correct.

The bigger picture

ABF and Primark are familiar names to most UK students. That familiarity is actually an advantage when learning to follow markets. It is easier to understand why consumers might be spending less in a particular shop when you have recently been in one than it is to grasp the same principle for an industrial component maker or a specialist chemicals company.

Following a brand you know, tracking its trading updates and results over time, and seeing how share price moves connect to the numbers being reported is one of the most effective ways to build genuine market intuition. Analysts spend careers studying these patterns; as a Student Investor Challenge participant, you have a rare opportunity to start that process now, in a risk-free environment with a virtual £100,000 at stake.

FAQ

What is a trading update?

A trading update is a short statement issued between a company’s full results — typically after a quarter ends — to give investors a snapshot of recent performance. It does not include full accounts. Instead it gives headline impressions: whether revenue is broadly in line with expectations, how key divisions are performing, and whether guidance is being revised. Trading updates often move share prices significantly because they signal whether the company is on track to meet, beat, or miss full-year forecasts.

What does like-for-like sales mean?

Like-for-like (LFL) sales measure revenue growth from stores that were open in both the current period and the equivalent period last year. New store openings are excluded. This matters because a retailer can report higher total sales simply by opening more locations, even if each existing shop is getting quieter. LFL strips out that new-store growth, showing whether the established estate is becoming more or less productive. A falling LFL figure is often interpreted as a sign that underlying consumer demand is softening.

What is a demerger?

A demerger is when a company splits one part of its business into a brand new, independently listed company. Shareholders end up holding shares in two separate businesses rather than one combined entity. Companies demerge when they believe the individual parts would be more highly valued on their own — because they attract different types of investors — than when they are bundled together. ABF is demerging Primark from its food divisions because the businesses appeal to very different investor profiles.

Why can shares fall even when a trading update says profits are on track?

Share prices reflect expectations, not just outcomes. If the market had priced in a chance of a guidance upgrade — a statement that profits would be better than previously forecast — then a statement saying profits are “broadly in line” registers as a mild disappointment, even though nothing has actually gone wrong. The price had already moved higher in anticipation of good news; when the good news does not arrive, some of that gain unwinds.