ISM vs S and P PMI: Two Surveys, Two Stories
Macro Glossary, Indicators and Reads
By Ken Chigbo, macro trader and founder of KenMacro, 18+ years in markets.
Updated 2026-05-20
The desk’s answer
Two PMI surveys cover the US manufacturing economy and they often disagree. The ISM (Institute for Supply Management) Manufacturing PMI is the older and more market-traded survey, with a 50 reading indicating no change from the prior month. The S and P Global US Manufacturing PMI (formerly IHS Markit) is the newer competitor, also 50-anchored but with a different respondent base, weighting, and sub-index treatment. At turning points the two surveys can read 4 to 6 points apart, with ISM historically running a cleaner cyclical signal but S and P Global more sensitive to current-month activity.
Defined term, ISM PMI vs S&P Global PMI
The ISM Manufacturing PMI is the diffusion index published monthly by the Institute for Supply Management, with a 50 reading indicating no change from the prior month, above 50 expansion, and below 50 contraction. The S&P Global US Manufacturing PMI is a competing survey from S&P Global with the same 50 threshold construction but different respondents, weighting and sub-indices, often producing divergent readings from ISM at economic turning points.
How the two surveys differ
ISM surveys roughly 300 manufacturing purchasing managers each month, with the headline PMI a composite of five equally weighted sub-indices (new orders, production, employment, supplier deliveries, inventories). The supplier-deliveries sub-index is inverted in the calculation (slower deliveries lift the index because they imply tight supply, i.e. demand strength). S and P Global surveys around 800 manufacturers and weights sub-indices differently. The result is two diffusion indices that aim at the same underlying activity but capture it through different lenses, producing 1 to 3 point divergence in stable regimes and 4 to 6 point divergence at turning points.
Which one moves markets
The ISM Manufacturing PMI is the older and more market-traded survey, with a 30-year history that traders trust for cyclical signals. A move from 49 to 51 (sub-50 to above-50) on ISM is a recession-or-recovery signal that can move the dollar and Treasury yields meaningfully. The S and P Global flash PMI (released a week before ISM) is the first read of the month’s activity and has grown in market influence since 2020, but the headline market reaction remains larger to ISM. When the two diverge, the market typically waits for ISM to confirm or refute the S and P Global signal before fully repricing.
Sub-indices that matter
Two ISM sub-indices carry independent market weight. New Orders (the leading indicator within ISM) often moves the dollar more than the headline, because forward orders are the cleanest read of momentum. Prices Paid (an inflation gauge) feeds directly into Fed reaction-function expectations; a hot Prices Paid reading is hawkish for the dollar even if the headline ISM is soft. The Employment sub-index is also tracked as a leading indicator for the NFP manufacturing payroll component released the following Friday.
Frequently asked
What is the difference between ISM and S and P PMI?
Both are US manufacturing diffusion indices with a 50 threshold separating expansion and contraction. ISM surveys 300 managers across five equally-weighted sub-indices and is the older, more market-traded survey. S and P Global surveys 800 managers with different weighting, releases earlier in the month, and is more sensitive to current-month activity.
Which PMI moves markets more?
ISM. Its 30-year history and traders’ familiarity make the headline ISM print the bigger market mover, particularly when it crosses the 50 threshold. S and P Global flash PMI is the first read of the month and has growing influence, but the larger market reaction remains to ISM.
Which sub-indices matter most?
New Orders (the leading indicator within ISM, often moves the dollar more than the headline), Prices Paid (a direct Fed-reaction-function input), and Employment (a leading read for the manufacturing payroll component of the following Friday’s NFP).
What this means at the desk
When ISM and S and P Global disagree, ISM is usually the survey that prices in.
Read next from the desk
Educational glossary entry only,
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