The eurozone's private sector closed the third quarter with its strongest expansion in more than three years, according to final purchasing managers' index (PMI) data for September, even as cost and price pressures accelerated further.

The final eurozone services PMI came in at 53.0 for September, unchanged from the preliminary estimate and up from 51.6 in August. The final composite PMI, which spans both manufacturing and services, was confirmed at 53.1, matching the flash reading and compared with 52.0 previously.

Broad-Based Expansion

The final figures reaffirmed the preliminary estimates, which showed private sector business activity rising at the quickest pace in nearly three-and-a-half years. Demand conditions continued to improve through September, capping a full quarter of growth and lifting the pace of increase to a 41-month high.

The recovery was broad-based: output expanded at faster rates in both the manufacturing and service industries at the end of the third quarter. The pattern was mirrored at the national level, with all five countries for which composite PMI data were available recording an expansion — the first such occurrence since November of last year.

Inflation Signals Complicate the Picture

Price pressures, however, continued to intensify in September. Input cost and output charge inflation accelerated sharply during the month, although both remained below the recent peaks reached in May.

The acceleration will continue to pose concerns for the European Central Bank (ECB) on the inflation front, after consumer prices already rose to nearly 4% last month — well above the ECB's 2% inflation target. Markets are now weighing whether core inflation, which strips out volatile energy and food prices, will also begin to accelerate. If it does, that would make it harder for the ECB to treat the current episode as primarily an energy shock.

What the Data Measure

The services PMI tracks business activity across the euro area's services sector, while the composite PMI combines services and manufacturing to provide a broader gauge of private sector economic activity. A reading above 50 indicates expansion, while anything below 50 points to contraction.

The data arrive in two stages each month: a preliminary "flash" estimate based on early survey responses, followed by a final reading that incorporates the full set of responses. In September, the final figures confirmed the flash estimates, leaving both the growth and price signals intact.

Why It Matters for Markets

The PMI surveys are among the earliest monthly indicators of how the eurozone economy is performing — a contrast with GDP, which is reported only quarterly. The September flash numbers were particularly notable because they suggested growth was accelerating rather than slowing, with the survey estimating that the findings were consistent with quarterly GDP growth of around 0.4%.

How This Fits the Broader Economic Picture

The emerging picture is increasingly one of stronger growth alongside stronger inflation pressure. Business activity improved across both manufacturing and services in September, new orders strengthened and employment edged higher. At the same time, firms reported faster increases in costs and selling prices.

So instead of weaker growth helping the ECB contain inflation, the latest data suggest the economy is holding up relatively well even as price pressures build.

Potential Market Impact

A stronger final reading, particularly if accompanied by further evidence of rising prices, would reinforce expectations that the ECB may need to tighten policy further. That would generally be supportive for the euro and could put upward pressure on European bond yields. Because these are the final estimates, however, it would take a sizable surprise to move markets materially; otherwise, the immediate impact should be largely negligible.

Current market relevance remains high: the ECB is caught between resilient economic growth and a renewed acceleration in inflation, meaning the PMI data feed directly into the debate over further rate hikes. The next round of eurozone inflation data will be watched to see whether the survey's price signals are corroborated by official readings.