Recent market volatility has revealed there are two types of millennial investor, said financial advisor Tess Downing of FJY Financial. Younger millennial clients recognize that they have long time horizons and are therefore willing to accept market volatility and not react to it.
"They're not that nervous about it," said Downing, adding that these millennials realize the market will go up and down many times before they retire.
But there's also a group of slightly older, slightly more jaded young people who started working right in 2008, when the markets last tanked. "They saw their 401(k) [plan] drop by 40 percent, 50 percent, and those are the ones that still haven't gotten over ... [that] bear market," Downing said.
Although these millennials recognize they have a long investment time horizon, they're still very conservative in their portfolio allocations.
"Over time, that's really going to hurt them, because they're not taking on the risk they need, to stretch for that growth that they need, for retirement," she said.
To help skittish millennials adhere to that long approach to capital management, FJY Financial puts a heavy emphasis on education. "We try to explain to them exactly how we invest portfolios, what is our belief in the markets," Downing said. 'We find that that education really goes a long way."
Looking ahead to the rest of 2016, Downing sees access to a globally diversified portfolio as being key — and that means "owning all the asset classes."
"We don't know which ones will outperform in 2016; therefore, we're going to give [clients] access" to a wide variety, she noted. "If someone tells you they know and they have the crystal ball, you should run in the opposite direction."
"A low-cost passive investment strategy while you're young to get you exposure to the markets is really what you need," she said.
— By CNBC's Kenneth Kiesnoski