The influential baby boomer generation appears to be sitting on the sidelines of the ETF investing trend. Even their elders are embracing ETFs at a faster pace.

Only 27 percent of baby boomers (aged 52 to 70) invest in ETFs, compared to 42 percent of millennials (aged 21 to 35) and 37 percent of "silvers" (aged 71 and older), according to the recently published BlackRock ETF Pulse Survey.

Baby boomers may be holding onto a "stock-picking mentality" after spending much of their lives in bull market territory, according to the report's authors.

BlackRock noted that its millennial and silver respondents appear to be embracing ETFs wholeheartedly, reporting a surge in ETF adoption among both generations. In a previous survey, only 33 percent of millennials and 22 percent of silvers reported owning ETFs.

Boomers also reported lower allocations to ETFs versus other generations. While millennials allocated an average of 18 percent of their assets to ETFs, and Generation X allocated an average of 19.2 percent, boomers reported an average allocation of 14.9 percent.

Overall, one-in-three respondents reported using ETFs, up from one in four in last year’s survey. ETF usage among women increased to 30 percent in 2017 from 23 percent in 2016. In the most recent survey, 62 percent of respondents said that they would buy ETFs in 2018, up from 52 percent.

BlackRock’s respondents seemed to be unaware of the different roles ETFs could play in their portfolios. Only one-third of respondents said they were using ETFs to generate portfolio income, while half of respondents were using individual stocks to generate income. Most respondents were unaware that ETFs track indexes, tend to have lower fees, can be used to reduce risk and are inherently tax efficient, according to BlackRock.

Most of the survey’s respondents, 65 percent, said that a mix of mutual funds and ETFs is the best approach to building a portfolio. When asked about beating the market, only one-fourth of the respondents thought they could successfully find active managers who would outperform the market.

BlackRock surveyed 1,000 U.S. investors online in August.