Individual investors in 17 countries polled by Natixis Global Asset Management in February said they looked forward to continued strong returns on their investments.
Eighty percent of respondents expected to do as well this year as last, if not better, and large numbers said equity markets would be this year's top performers.
The survey suggested, however, that investors' optimism may be leading to unrealistic expectations.
In the new survey, investors believed that the average annual return they would need to meet their goals was 9.7% above inflation, compared with the 9% they anticipated in Natixis's 2014 survey.
"Investors have gotten used to excellent stock market returns in the last few years, so their view of financial markets is notably positive," John Hailer, the firm's chief executive for the Americas and Asia, said in a statement.
"At the same time, many investors remember seeing significant losses in their portfolios after the global financial crisis. The missing piece is that many haven't really planned, or prepared themselves emotionally, for another market setback."
This year's survey found investors more conflicted between chasing performance and protecting capital than they were two years ago. The number who said they would choose safety over high returns also increased, to 84% this year from 78% in 2014.
Resolving their conflicted feelings won't come easily, the survey found, as many investors appear to rely on broad return assumptions and emotional measures of risk that could undermine their success.