The falls were particularly marked in Europe and Asia, while North America rebounded slightly, according to a statement from State Street.
In Europe, the Investor Confidence Index (ICI) dropped by 8.2 points to 105.9, its lowest level since April 2014.
State Street senior vice president and head of global macro strategy Michael Metcalfe said the fall could have a number of explanations.
“This suggests either that investors are not as complacent about events in Greece as some bond spreads suggest or that the promise of QE in Europe has proved more alluring than its reality,” he said.
“Neither interpretation is particularly good news.”
In Asia, confidence levels fell by 5.3 points to 93.8, below the reading of 100 which is considered ‘neutral’ on the index.
North America, on the other hand, saw confidence measures climb by 3.1 points to 104.3.
State Street’s Kenneth Froot, who developed the index, suggested US confidence readings were being inflated by the North American region more generally.
“However, given the lack of inflationary pressures in the US, markets may push out their expectation of the first interest rate hike to later than the previously anticipated June date, which could provide a lift to sentiment,” he said.
The ICI measures confidence or risk appetite quantitatively by analysing the buying and selling patterns of institutional investors, according to the statement.
