This survey is highly respected due to its large sample size and historic correlation with German and wider Eurozone economic conditions. It tends to create a hefty market impact upon release. Source changed series from a base year of 2000 to a base year of 2005 as of May 2011;
Why Traders
Care It's a leading indicator of economic health - businesses react quickly to market conditions, and changes in their sentiment can be an early signal of future economic activity such as spending, hiring, and investment;
Derived Via Survey of about 7,000 businesses which asks respondents to rate the relative level of current business conditions and expectations for the next 6 months;