Warehouse on Wheels (WOW), the largest independent storage trailer rental network in North America, today announced the September 2026 WOW Supply Chain Activity Index, a monthly composite indicator of U.S. supply chain activity.

The September index recorded an August 2026 data reading of 43.7, up 7.2 points from the previous reading of 36.4 and the highest level since February 2023. The gain reversed July's sharp decline and lifted the index 10.3 points above its January 2026 cycle low of 33.4. WOW's proprietary Deployment Ratio drove most of that rise, going from 0.75 to 1.18 as dry van on-rents outpaced dry van off-rents for the first time since March. The eight public data series added only about 1.2 points combined. The reading remains inside the Contraction zone, where it has been since early 2023.

"Our trailer data showed positive movement before the macro data did," said John Brooks, CEO of Warehouse on Wheels. "Dry van on-rents beat dry van off-rents in August for the first time since March, and that shows up in our yards a month before it reaches the other data points. This means the market is willing to add capacity again, but only capacity it can hand back, which is where every recovery starts. It's important to note that one month doesn't make a turn, so we're watching September."

August 2026 Supply Chain Market Signals:

- WOW's own data moved first. The Deployment Ratio accounted for 6.0 of August's 7.2-point gain, far more than any public series contributed, an indication that trailer demand turned before the broader indicators registered it.

Supply chain activity remains in contraction. The 43.7 reading falls between 30 and 45, the Contraction zone, and sits at the top of that band rather than crossing into Neutral territory above 45.

- The public data was mixed. Cass Freight Index shipments rose and LMI Transportation Prices firmed to 90.0, but ISM Manufacturing PMI slipped to 54.6 and LMI Warehousing Utilization fell from 66.1 to 59.6. Warehouses reported themselves less full in August even as trailer deployment climbed.

- The next several readings will be critical. The index is averaging 39.6 across the first eight months of 2026, and one month above that average is not a trend. A second reading at or above 43 next month would confirm the turn, while a slide back into the high 30s would mark this as a one-month spike.

- The WOW Supply Chain Activity Index is compiled from nine weighted data series, including WOW's own Deployment Ratio, LMI Warehousing Utilization and Transportation Prices, the Cass Freight Index for shipments, and broader manufacturing and industrial indicators, combined into a single monthly reading on a 0 to 100 scale.