The ECB's September meeting has become a useful map of how an external shock travels through a modern economy. The immediate event is simple: markets expect the deposit rate to rise by 25 basis points to 2.50% on 10 September. The underlying route is more complex, running from energy supply through inflation, corporate pricing, credit conditions, bond markets and eventually investment decisions.
Euro-area inflation rose to 3.3% in August from 2.9% in July. Energy was the dominant driver, accelerating to 14.3% year on year. Services inflation eased to 3.0%, while non-energy industrial goods rose 1.2%. This mix matters because the ECB is not facing a classic demand boom. It is trying to stop a supply shock from becoming embedded in the rest of the price system.
The Governing Council raised rates in June, then held in July. The deposit rate remains 2.25%, with the main refinancing rate at 2.40% and the marginal lending rate at 2.65%. The July account records unanimous support for the pause and repeatedly stresses that decisions will remain data-dependent and meeting by meeting.
That is not rhetorical caution. The ECB has to judge three separate stages of transmission. First is the direct effect of energy on consumer prices. Second is the indirect effect on transport, production and services. Third is the possibility of second-round effects, where firms and workers start setting prices and wages on the assumption that inflation will remain high.
The institution's June forecasts captured the tension. Headline inflation was projected at 3.0% in 2026, 2.3% in 2027 and 2.0% in 2028. Growth was expected at only 0.8%, 1.2% and 1.5% over the same period. Tightening policy in that environment is a trade-off: the ECB wants to preserve price stability without turning a supply shock into an unnecessary demand slump.
Financial conditions are the bridge between the policy rate and the real economy. Mortgage demand had already declined by July, and banks tightened mortgage credit standards in the second quarter. Corporate borrowers face the same direction of travel through higher refinancing costs and more demanding investment thresholds.
The market has largely settled the immediate question. Pricing as of 4 September put the probability of a September increase to 2.50% at 100%. But the path beyond that is not fixed. Recent policymaker comments have kept further tightening on the table if inflation risks worsen, while the ECB's own survey of professional forecasters still showed 2.50% as the modal level around the turn of 2026-27.
That creates two competing routes. In the first, energy prices stabilise, long-term inflation expectations remain anchored near 2%, and the ECB can hold around 2.50% before gradually easing. In the second, the shock lasts long enough to reshape contracts, wages and pricing behaviour. The deposit rate would then need to stay higher for longer, with additional hikes becoming plausible.
For global investors and companies, the distinction affects more than European borrowing costs. It changes relative bond yields, the price of euro funding, capital allocation and demand across one of the world's largest trading blocs. A temporary energy shock can be absorbed. A persistent one rewrites balance-sheet assumptions.
The Berlin meeting will therefore be less about whether the ECB moves by 25 basis points than about which transmission route it believes Europe is now on. The new projections and the description of underlying inflation will offer the clearest signal of whether 2.50% is a destination or merely the next junction.