The mood among German investors worsened for the third consecutive month in August, according to a new survey.
The research suggests markets expect Europe's biggest economy to lose some momentum in the coming months.
The Mannheim-based ZEW research institute said its monthly survey showed its economic sentiment index fell to 10.0 from 17.5 in July.
This undershot a Reuters consensus forecast for a fall to 15.0.
A separate gauge measuring investors' assessment of the economy's current conditions edged up to 86.7 from 86.4 last month.
This compared with the Reuters consensus forecast predicting a dip to 85.5.
This comes despite a report yesterday from the German Central Bank, the Bundesbank, which said the domestic economy could grow faster this year than earlier expected on the back of exceptionally strong industrial production, exports and consumption.