What Is PMI? Purchasing Managers' Index Explained

The Purchasing Managers' Index (PMI) is a monthly economic indicator that tracks changes in business conditions across sectors such as manufacturing and services. S&P Global compiles PMI data for more than 40 economies using surveys of senior executives at private-sector companies. A reading above 50 generally signals expansion, while a reading below 50 indicates contraction. With PMI explained in these simple terms, it's easy to see why the release finds its way onto so many trading calendars.

For traders, PMI can provide an early indication of changes in economic activity before many official statistics, such as quarterly gross domestic product (GDP), are released. However, PMI announcements can also cause short-term market volatility, particularly when the figures differ significantly from expectations. Spreads may widen and fast-moving prices can increase the risk of slippage.

What Is the Purchasing Managers' Index (PMI)?

So what does PMI mean in practice? The Purchasing Managers' Index, usually shortened to PMI, is a survey-based economic indicator designed to provide a timely view of changing business conditions. In short, the PMI meaning comes down to one question: are businesses reporting more improvement or more deterioration than the month before?

Each month, participating companies report whether selected business measures have increased, decreased or remained unchanged compared with the previous month. These responses are converted into diffusion indices, allowing analysts to see whether activity is generally expanding or contracting.

The exact variables depend on the sector. Manufacturing surveys cover areas such as output, new orders, employment, purchasing activity, inventories, prices and supplier delivery times. Services surveys include business activity, new business, employment and prices, among other measures.

In US mortgage lending, PMI can also stand for Private Mortgage Insurance. In economic calendars and financial-market analysis, however, PMI normally refers to the Purchasing Managers' Index.

How to Read PMI: The 50-Level Diffusion Index Threshold

PMI does not measure the absolute value of economic output. Instead, it measures whether surveyed business conditions have improved, remained unchanged or deteriorated compared with the previous month.

S&P Global calculates individual diffusion indices using the proportion of respondents reporting an increase, no change or a decrease. The central threshold is 50.0.

For example, a reading of 54.0 indicates expansion, while a reading of 46.0 indicates contraction. In general, the further an index moves away from 50.0, the stronger the rate of change indicated by the survey responses.

The headline figure does not always tell the whole story. PMI sub-indices can provide useful context on what is driving the overall reading.

For example, S&P Global's Manufacturing PMI is a weighted combination of five components. New orders carry the largest weight at 30%, followed by output at 25%, employment at 20%, suppliers' delivery times at 15% and stocks of purchases at 10%. Supplier delivery times are inverted when calculating the headline index.

This means a headline Manufacturing PMI can remain above 50 even if the New Orders Index has moved below 50, provided other components remain strong enough. Falling new orders may suggest that incoming demand is weakening, but it does not by itself mean that production will immediately contract. If weaker demand persists, however, businesses may eventually respond by reducing output or employment.

Key PMI Types: Manufacturing, Services and Composite

PMI surveys are produced for different sectors, allowing analysts to examine where economic activity is strengthening or weakening.

Manufacturing PMI

Manufacturing PMI measures changes in conditions in the goods-producing sector.

S&P Global's headline Manufacturing PMI combines five components: new orders, output, employment, suppliers' delivery times and stocks of purchases. Other survey indices provide additional information on areas such as export orders, input costs, selling prices and purchasing activity.

Manufacturing can be sensitive to changes in interest rates, global demand, trade conditions, energy costs and supply-chain disruption.

Services PMI

Services PMI tracks activity in service-sector businesses. Depending on the survey, this can include measures such as business activity, new business, employment, outstanding work and prices.

Services data can be particularly important in economies where the sector represents a large share of economic output. In the UK, for example, services have accounted for around 80% of economic output in recent years.

Composite PMI

A Composite PMI combines manufacturing and services data to provide a broader view of private-sector activity.

S&P Global calculates its composite measures using weights based on each sector's contribution to GDP or gross value added. This helps the index reflect the relative economic importance of manufacturing and services.

Flash PMI vs Final PMI

For several major economies, S&P Global publishes PMI data in two stages.

1. Flash PMI: An early estimate published approximately one week before the final figures. It is typically based on around 85%–90% of the responses eventually included in the month's survey.
2. Final PMI: Published later using the fuller set of responses and therefore capable of revising the preliminary Flash figure.

Flash manufacturing, services and composite PMIs are currently published for markets including the UK, US, eurozone, France, Germany, Japan and Australia.

Because Flash PMI is the first indication of that month's business conditions, it may attract greater market attention. However, the size and direction of any market reaction depend on how the result compares with expectations and what investors were already pricing in.

Who Releases PMI Data? ISM vs S&P Global

S&P Global and the Institute for Supply Management (ISM) are two widely followed producers of purchasing managers' surveys, but their coverage and methodologies are not identical.

S&P Global

S&P Global produces PMI data for more than 40 economies, including the UK, US, eurozone, China, Japan and a range of emerging markets. Its cross-country framework allows analysts to compare business conditions across different economies using broadly consistent survey principles.

Institute for Supply Management (ISM)

In the US, the Institute for Supply Management publishes the ISM Manufacturing PMI Report and ISM Services PMI Report.

ISM's economic indicators date back to 1931 and remain widely followed measures of US business conditions. Its Manufacturing PMI is a composite of five equally weighted indices: New Orders, Production, Employment, Supplier Deliveries and Inventories. Its Services PMI uses four equally weighted components: Business Activity, New Orders, Employment and Supplier Deliveries.

S&P Global also publishes US PMI data, so traders reading an economic calendar should check which organisation produced the figure rather than assuming all US PMI releases use the same survey or methodology.

Why PMI Matters for CFD Traders

PMI matters to you as a trader because it provides relatively timely information about economic conditions. It may offer clues about growth, employment, demand, supply constraints and price pressures before some official economic statistics are released.

For CFD traders, the importance of a PMI announcement usually depends less on whether the figure is simply above or below 50 and more on how it compares with market expectations, previous readings and relevant sub-indices.

PMI data can also affect expectations for central bank policy. For example, strong activity combined with persistent price pressures may lead markets to reassess the likely path of interest rates. However, policymakers consider a wide range of economic data, so a single PMI release should not be treated as a reliable predictor of an interest-rate decision.

When PMI differs materially from forecasts, several markets may react:

• Foreign Exchange (Forex): Stronger-than-expected data may support a currency if it leads markets to expect stronger economic growth or tighter monetary policy. The opposite may occur after weaker data, but the reaction depends on market positioning and the wider economic outlook.
• Stock indices: Strong business activity may be positive for earnings expectations, but it can also increase concerns about inflation or higher interest rates. As a result, the same PMI result can have different effects depending on market conditions.
• Commodities: Manufacturing PMI can influence expectations for industrial demand, particularly when data come from large manufacturing or commodity-consuming economies. However, commodity prices are also affected by supply conditions, geopolitics, inventories and other factors.

PMI should therefore be viewed as one input in a broader market analysis rather than a standalone trading signal.

Execution Risks During PMI Releases

If you trade short-term around major economic announcements, you're taking on additional execution risk.

Liquidity conditions can change quickly around a PMI release. Bid-ask spreads may widen, increasing trading costs, while rapid price movements can lead to slippage, meaning an order is filled at a different price from the one expected.

Leverage increases this risk because it magnifies both potential gains and losses. Traders should therefore consider position size, available margin and possible price gaps before opening a leveraged position around a scheduled announcement.

For UK-regulated CFD providers, there is no single Financial Conduct Authority (FCA)-mandated market-wide percentage stating that a fixed proportion such as 70%–80% of all retail CFD accounts lose money. Instead, FCA rules require each provider to display its own up-to-date percentage of retail client accounts that lost money. The calculation must be updated every three months and cover the preceding 12 months.

Historical research by the European Securities and Markets Authority (ESMA) found that 74%–89% of retail CFD accounts typically lost money across the EU jurisdictions it examined. That range is useful historical evidence of the risks involved, but it should not be presented as a current FCA or ESMA limit, cap or universal loss rate.

Conclusion

Now that we've answered what is PMI and how the 50-level threshold works, one thing is clear: readings above 50 generally signal expansion, while readings below 50 indicate contraction — but the headline figure is only part of the picture.

Looking at sub-indices such as new orders, employment and prices can provide more context on the forces driving the headline result. Traders should also compare PMI with market expectations and other economic indicators rather than using it as a standalone signal.

Whether you follow S&P Global surveys or US ISM releases, PMI can help provide context for changes in growth, inflation and monetary-policy expectations. For more information on how derivative markets work, see our guide to CFD trading.

Trading CFDs and other leveraged products involves a high risk of loss. Short-term volatility around economic releases can increase spreads, slippage and the risk of rapid losses, so risk management remains important.