It’s the top of a new month, meaning we get to see the latest manufacturing purchasing manager’s index (PMI) readings. And if you follow both the Institute for Supply Management (ISM) and IHS Markit’s reports on U.S. factory activity, you may be getting some mixed signals.

First let’s look at the ISM report. As of November, the manufacturing PMI has now been below the key 50.0 threshold for four straight months, making this the 11th longest-running period of month-over-month contraction of the past 40 years.

Longest-running U.S. Manufacturing Contarctions of the past 40 Years
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The gauge registered 48.1, down from October’s 48.3 and below expectations of 49.4. This marks the fourth consecutive month of industry contraction. The current four-month period ties in length with two previous periods—one from March to June 2008, the other from December 2015 to March 2016—and is the 11th longest overall going back to 1979.

Manufacturing executives were less than optimistic in their responses. Here’s just a sampling: “Economic uncertainty continues… Slowdown in business has us revising our 2020-21 capital spend… The order book continues to shrink below our forecast levels… Profits are elusive… Tariffs are still a question.”

Although not every period of sustained ISM manufacturing contraction has been accompanied by an economic recession, each one has coincided with a stock market slowdown or pullback. During the last significant contractionary period from December 2015 to March 2016, the S&P 500 underwent three straight months of declines.

Stocks sold off Monday and Tuesday following November’s poor ISM manufacturing data, but it’s still too early to say whether a trend is developing.