US business inventories up 0.4% in August, matching forecasts

• The prior reading was +0.8%
• Retail inventories excluding autos compared with +0.8% previously

For context, the Census Bureau puts out the US business inventories report — formally called the Manufacturing and Trade Inventories and Sales release — on a monthly basis, roughly six weeks after the reference month closes. The data brings together inventory and sales figures for manufacturers, wholesalers and retailers, the three sectors that hold most of the goods in the US economy.

Much of the content is familiar by publication time. Factory orders data already included manufacturing inventories. The Advance Economic Indicators release, arriving about four weeks after month end, carries early wholesale and retail inventory estimates. Business inventories fills in the last retail details and the overall total, so it seldom has much effect on markets.

The main numbers to watch are the month-over-month change in total inventories and the inventory-to-sales ratio, which shows the number of months needed to sell through current stock at the latest sales run-rate. A higher ratio could point to softer demand or intentional building of stock. A lower ratio suggests thin inventory and a possible need to replenish.

The report's chief use is for tracking GDP. Private inventory changes are among the most volatile elements of quarterly growth, capable of shifting the overall figure by a percentage point or more. Economists lean on the monthly readings, especially retail inventories excluding autos, to sharpen their GDP projections. The dollar-based figures mean periods of fast goods inflation can lift inventory values even when physical stock is unchanged.

Inventory swings have gained more significance in recent years, with businesses moving ahead of tariffs, rebuilding supply chains and adapting to changing trade policy, all of which have caused big distortions in quarterly GDP numbers.