Active Trader has analyzed dozens of market events, including most major economic reports, and found several intriguing patterns. For example, the S&P500 tends to rally when the Institute of Supply Management (ISM) releases its manufacturing report on the first day of the month. The S&P also tends to climb as the Fed announces interest–rate decisions (at least initially) and as monthly producer price index (PPI) numbers hit the Street, while it tends to remain flat in response to consumer price index (CPI) values.

But how has the market reacted when there’s no economic news? We studied Briefing.com’s economic calendar over the past eight and a half years and measured how the S&P500 behaved on days in which no economic news appeared vs. days in which some type of economic report emerged. Then, the study compared how the S&P performed in the absence of economic news to its behavior on each of the major release days: Fed announcements, jobs, GDP, inflation (CPI and PPI), and ISM manufacturing.

Overall, the differences are subtle but worth exploring, because the market tends to move in one direction in response to economic news and in the opposite direction when news is scarce.