Wholesale price index

An index of prices at the wholesale level, dominated by manufactured goods and commodities rather than services.

If you're analysing a company, it's often more useful than the consumer index, because it follows input costs directly. A manufacturer's gross margin usually correlates better with wholesale inflation than with consumer inflation.

When the two indices diverge, the gap is itself a signal: wholesale running far above consumer means input costs are rising faster than companies can pass them on, and margins are about to compress.

Watch the spread between them.