Generation X isn’t getting much sleep lately — maybe that’s why American Funds has labled them “Generation AnXious.”

According to recent research from the Los Angeles-based active investment manager, Gen Xers, now between the ages of 37 and 51 years old, is feeling the most stressed by planning their financial future.

In “The Wisdom of Experience: Lessons Learned from Millennials, Generation X and Baby Boomer Investors,” 63 percent of generation X respondents said that they were kept up at night thinking about financing their retirement. Around half of the survey’s other respondents felt the same: 53 percent of millennials ages 21 to 36, and 45 percent of baby boomers aged 52 to 70, are kept up at night by their retirement concerns.

More than 30 percent of Gen Xers in the survey felt worried that they’re not earning enough money to be able to invest for the future, and around one-quarter are concerned that they will not be able to pay off their own debts and finance their children’s aducation.

All that uncertainty makes Generation X more likely to seek outperforming mutual funds, said Heather Lord, senior vice president and head of strategy and innovation at American Funds’ parent company Capital Group, in released comments.

"After experiencing the dot-com bust, the global financial crisis and the housing collapse, as well as stagnant wage growth during their formative adult years, Gen Xers are wary about their financial future," said Lord. "Perhaps because of these concerns, Gen Xers long to do better than the average market and say actively managed funds can help them reach these goals.”

Age and gender played a role in respondents’ views about the future.

Men were more confident than women that the market would continue to go higher over the next decade -- 67 percent of male respondents expect the market to continue its rise compared to 51 percent of female respondents.

When asked about their outlook over the next 25 to 30 years, on the other hand, women in the survey displayed levels of optimism on par with men. Fifty-seven percent of both sexes said that they expected the market to continue to go higher over the next two to three decades.

Over the next decade, only 16 percent of baby boomers expect the markets to repeat the relatively strong returns of the past five years. Millennials were nearly twice as optimistic -- 31 percent believed that the market would continue its run over the next decade.

Almost half of boomers, 48 percent, expected market returns to be lower than historical averages over the next two to three decades compared to 29 percent of millennials and Generation xers.

When asked about their retirement, on the other hand, the generational optimism was reversed: 61 percent of boomers expected that they would feel satisfied on the 100th day of their retirement, versus 40 percent of Generation x and 43 percent of millennial respondents.

When it comes to savings, millennials are learning the lessons of their elders -- 59 percent of millennial respondents had started saving before the age of 25, compared with 42 percent of generation X and 28 percent of baby boomers. Of all the generations, millennials were also the most likely to reach out to an advisor during market fluctuations.

Majorities in all three generations studied by American Funds said that they would like to generate alpha in their portfolios through the use of some actively managed products  -- 69 percent of respondents overall said that by mixing passive and active funds, they could achieve better returns.

Yet American Funds’ survey found most investors unsure of how to distinguish between mutual funds. Nearly 80 percent of respondents couldn’t identify the link between attributes like low fees and high manager ownership as success factors for actively managed funds. 

More than two-thirds of respondents, 67 percent, said that low fees and a track record of outperforming market benchmarks were important to them.

Most investors, 64 percent, said that they felt more comfortable investing in a fund where the manager’s own money is invested along side their own and agreed that those fund managers were more likely to do well for investors.

While most investors, 75 percent, also said they wanted funds that offered some downside protection, only 54 percent were aware that index funds generally exposed them to the full impact of volatility.

Baby boomers, at 36 percent, were the most likely to value a financial advisor's advice when selecting mutual funds. Less than a quarter of millennial and Gen X respondents said they consulted advisors before selecting mutual funds,

For the survey, 1,203 American adults were interviewed online in July 2016.