It all paints a somewhat complicated picture that shows investors still aren't convinced that the coast is clear. (Read the full report here.)
"Maybe the conclusion we can draw is that even with very good returns, there are still some things looming on the horizon with the U.S.," Carter Sims, head of U.S. Intermediary Distribution at Schroders, said in an interview. "We all have enough scars from 2008."
Leading concerns for American investors are taxes as well as the state of the global and domestic economies. Inflation fears coupled with interest rates also ranked in the top five, while the Middle East turmoil is also on many minds.
Despite all their misgivings—and adding to the contradictions of prevailing sentiment—56 percent of respondents believe U.S. equities are the best place to be. The next-most popular spot is multi-asset funds, which Sims said is consistent with what he's seen from client behavior.
Emerging market equities also are popular, despite a historically long spell of fund outflows over the past four months.
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Fixed income is one of the least popular, though investors still want exposure.
"We still feel as a company there's a lot of money on the sidelines," Sims said. "People are really looking to diversify, realizing you can't be all in fixed [income] and you can't be all in equities. That's why you see the interest in multi-asset products."
One root of the lack of confidence, then, simply could be that investors don't believe the stock market can replicate its 2013 performance and not necessarily that things are going to turn ugly.
The year so far has been a shaky ride, with a rough January giving way to a stellar February.
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Investors overall seem willing to take that ride, though they may not be happy about it.
"It was a very good year in 2013 as it related to the market, for those who participated," Sims said. "Back-to-back years [like that] don't really happen a lot."
—By CNBC's Jeff Cox. Follow him on Twitter @JeffCoxCNBCcom.