What is a flash PMI, and why do the numbers get revised? Explain it simply

A flash PMI is an early survey of businesses, published before the full version. S&P Global's flash UK composite for October was 53.1, and its flash euro area composite was 51.9 (UK flash, euro area flash). Those are early readings, and the final figures can differ.

The survey asks purchasing managers whether output, orders and staffing are higher, the same or lower than a month ago. A reading above 50 means more firms reported growth than contraction. The flash comes early so that traders get a view before the full survey is in. Its final version is published later and can differ, so the flash is best treated as an early view.

We would like the friendliest explanation in the community:

• How would you explain a PMI to someone who has never read a survey?
• Why do you think early readings get revised?
• Which PMI line do you look at first: the composite, services or manufacturing?
• What is one thing you wish you had known about PMIs when you started?

PMIs explained gives the full method.

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