NEW YORK (TheStreet) -- It's fine for millennials to buy shares of their favorite technology brands as long as they don't go overboard, says Nicole Sherrod, Managing Director of Trading at TD Ameritrade.

"We focus on educating our clients on risk management and position sizing, so we are trying to make sure the mistakes of the Internet bubble are not repeated," says Sherrod. "What young people are really focused on is understanding the companies behind the technologies they use every day."

Millennials are the generation that reached adulthood around the year 2000 so they may not have lost money the last time tech fever swept the investing world. Unlike their parents. Nevertheless, one stock which boasts multi-generational appeal is Apple (AAPL - Get Report).

"The boomers and millennials overlap when it comes to Apple," says Sherrod. "Parents and kids both have iPhones and that's the No. 1 holding across our customer base."

Sherrod says TD Ameritrade clients have more than $19 billion invested in Apple. Yet while Apple products have retained their cool factor across generations, many younger Facebook (FB - Get Report) users are abandoning the service now that their parents and grandparents are adopting it. That's not affecting the stock right now, but it could in the future, says Sherrod.

"What's really interesting is that Boomers have been investing more and more in Facebook," says Sherrod. "The company has moved up 5 positions on our list of most-held stocks by Boomers. I think they see the power of this technology so they are investing more in the stock."

Facebook was slightly lower following a mixed earnings report yesterday after the closing bell. Net income of 42 cents a share beat estimates by 2 cents, while revenue of $3.54 billion missed by $20 million. Sales rocketed 41.6% higher year over year.

Facebook competitor Twitter  (TWTR - Get Report) reports first-quarter earnings on April 28. Sherrod says ownership of the social media company skews younger, but it could soon rise among the Boomer ranks as well.

"Twitter skews toward the millennials and their new Periscope technology is resonating with younger users," says Sherrod. "The company has made a lot of progress in the quarter with respect to advertising so that will be one to watch."