The second estimate for May wholesale inventories is unchanged from the first estimate, at a sizable 0.6 percent build. This is up from April's 0.2 percent build.

Both durables and nondurables posted similar builds in May, 0.6 and 0.7 percent respectively. Autos continued to build, up 1.4 percent after April's 1.9 percent.

Sales at the wholesale level rose 0.4 percent in May following April's 0.2 percent rise.

Wholesale trade measures the dollar value of sales made and inventories held by merchant wholesalers. It is a component of business sales and inventories.

Investors need to monitor the economy closely because it usually dictates how various types of investments will perform. The stock market likes to see healthy economic growth because that translates to higher corporate profits. The bond market prefers a slower rate of growth that won't lead to inflationary pressures. Wholesale sales and inventory data give investors a chance to look below the surface of the visible consumer economy. Activity at the wholesale level can be a precursor for consumer trends. In particular, by looking at the ratio of inventories to sales, investors can see how fast production will grow in coming months. For example, if inventory growth lags sales growth, then manufacturers will need to boost production lest product shortages occur. On the other hand, if unintended inventory accumulation occurs (i.e. sales did not meet expectations), then production will probably have to slow while those inventories are worked down. In this manner, the inventory data provide a valuable forward-looking tool for tracking the economy.