The State Street Investor Confidence Index for July inched up 2.2 points to 101.1, State Street Global Markets reported Tuesday. However, in North America, the index fell 1.3 points to 99.2.

In Europe, investors continue to be more optimistic, with that index rising 10.5 points to 98.1.

The index measures the actual buying and selling patterns of institutional investors, with a reading of 100 being neutral.

“This month, institutional investors were reacting strongly to the differential risk outlooks in Europe and the U.S.,” said Harvard University Professor Kenneth Froot, who developed the index along with Paul O’Connell of State Street. “In an environment in which major country policymakers are grappling with sovereign debt and deficit issues, the influence of a few pieces of news can be enormous. The added policy risk in the U.S. and Europe has institutional investors in a reactive mode, trying to position and then reposition as the situation changes.”