Market research group Sentix released its investor confidence index for the Eurozone on Monday. The index rose to 9.9 in June from 6.2 in May, exceeding expectations for an increase to 7.1. It was the highest level since December 2015.

A reading above 0.0 indicates optimism, below indicates pessimism.

"Investors' perception brightens with regards to both current situation and expectation values," Sentix said in its statement.

The current conditions index was up to 9.8 in June from 7.0 in May.

The expectations index climbed to 10.0 in June from 5.5 in May.

German investor confidence index rose to 20.7 in June from 18.3 in May.