The Most Important Economic Indicator You’ve Never Heard Of

Famed investor Stanley Druckenmiller once remarked, “The best economist I know is the ISM.” He has long noted that while the stock market follows the economy, the ISM leads it. So, what is the ISM? The Institute for Supply Management (ISM) conducts a massive monthly survey of hundreds of Purchasing Managers, which are the executives responsible for buying the raw materials and supplies that keep companies running.

Because these managers are the first to know if their company is scaling up (growth) or pulling back (trouble), their responses serve as an early indicator for the U.S. economy. These responses are distilled into several indices where a reading above 50 indicates expansion and below 50 indicates contraction.

Manufacturing to Ramp Up

After a year of sluggishness, the U.S. manufacturing sector sprang back to life in January 2026. The headline index jumped unexpectedly from 47.9 in December to 52.6, driven by a massive spike in new orders.

The ISM New Orders Index is a critical leading indicator because new orders today become production and gross domestic product (or GDP) tomorrow (see figure 1). Combined with a 1.5% boost from the federal government reopening, these data lend credibility to Commerce Secretary Howard Lutnick’s recent comments that the $30 trillion U.S. economy could potentially exceed 5% growth in Q1 2026 (versus expectations for 3.0% growth in Q4 2025 which is set to be released a day after this publication).

Figure 1. Real U.S. Gross Domestic Product vs. Weighted ISM New Orders Index*