Acorns, a micro-investing mobile app, announced it has raised $30 million in financing, including strategic investments from PayPal and Rakuten Fintech Fund. Through this investment, Acorns said in a press release it will expand its automated investment features to make gathering and growing funds easier for users.

"Acorns and PayPal share a vision of democratizing financial services and offering innovative solutions to help people build financial health," said Joanna Lambert, vice president of global consumer product and engineering at PayPal. "Technology is breaking down barriers to financial participation. PayPal is excited to support Acorns as they continue to use mobile technology to innovate in micro-investing, and empower millennials to take charge of their finances."

More than 850,000 people have opened investment accounts with Acorns since the app launched 20 months ago, according to the announcement. Acorns highlights a feature called Invest the Change, which rounds up everyday purchases and invests the difference, and education initiatives like Grow, the first digital magazine dedicated to helping millennials navigate complex financial decisions. Nearly 75 percent of Acorns users are between the ages of 18 and 34. 

"Having PayPal and Rakuten as partners will make it possible to bring the benefits of micro-investing to more and more people around the world," said Acorns co-founder and CEO Walter Cruttenden, who is moving into the role of chairman. "We believe that micro-investing will ultimately comprise the majority of new investment dollars entering the markets."