NEW YORK ( MainStreet) — Investors are becoming more apprehensive about the markets, according to a comprehensive new study.

The Wells Fargo/Gallup Investor and Retirement Optimism Index fell eight points during second quarter, from +37 to +29. This was largely on the heels of a 17 point decline among retirees’ sentiment in the study, which fell 17 points.

Still, 84% of the 1,036 investors in the survey believe the American Dream is still attainable. Almost all respondents characterized the American Dream as living comfortable during retirement.

Some 90% of non-retiree respondents were optimistic about their prospects for achieving the American Dream, compared to only 77% of retirees.

A substantial portion of respondents, 46%, feared they would run out of money during retirement.

“Longevity is key to retirement investing,” says Tammy Sweet Halprin, senior vice president – investments at Wells Fargo Advisors. “You may live into your 90s and need to make sure you’re saving enough to cover health care costs, which still remains a big unknown.”

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She says some of her retired clients have pensions, but are reluctant to spend the money, for fear of increased health care costs in the future and the possibility of nursing home expenses.

The survey also examined what investors would do with $10,000. Some 41% said they would invest in the markets, while 56% opted to save it as liquid cash or keep it on the sidelines in a CD.

“People are a little nervous and still vividly remember how much they lost in 2008 and they’re waiting for the next shoe to drop given how high the markets went up as of late,” Halprin adds. The major stock indices have been on a record breaking streak this summer, causing many investors to wonder how much higher the markets can go.

The respondents who would have invested money in the markets at the start of the year would have seen healthy, but not jaw dropping returns. After all the Dow Jones Industrial Average is up 2.8% year-to-date and the broad S&P 500 is up 7.8%. Both yields significantly eclipse the paltry returns in a savings account or CD.

Among the 80% of respondents who own stocks, an overwhelming majority, 71% opted to seek advice of a professional, compared to just 27% who felt comfortable enough investing by themselves. Most respondents tend to consult an expert or advisor during significant life transitions, such as retirement (71%), divorce (64%) or the passing of a family member (52%).

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“Investors are knowledgeable about the markets or a certain stock, but they may not know what to do,” Halprin says. “The main goal of retirement is to convert an investment that creates a steady stream of income each month.”