This robo-adviser just raised $100 million in its latest funding round

Betterment, a startup that uses technology to automate financial planning, just raised $100 million in a Series E round of funding.

Leading the investors is Sweden's Kinnevik. Previous investors including Bessemer Venture Partners, Menlo Ventures, Anthemis Group and Francisco Partners participated.

The round values Betterment, the largest of the independent robo-advisers, at $700 million. That's up from a $400-$500 million valuation after its Series D funding round a year ago.

"To us it feels like a validation of the growth that we've had over the last year and some of the product enhancement that we've rolled out" CEO Jon Stein told Business Insider.

The funding round is notable given the unusually tough market environment. Many venture capitalists are backing away from investing in the private markets following exploding private valuations for startups in recent years.

"The markets have been frothy," Stein said, adding that during their Series D round they could have pushed for a higher valuation, but chose to go with a more conservative price.

"I think that that decision really put us in a good spot going into this round of funding, because people understood the story, they understood how we continued to grow," he said.

Betterment manages clients' money by investing in ETFs. Based on client goals, it uses technology - rather than human financial advisors - to automate investing decisions.

But it is also expanding into other advisory roles, and Stein said he aims to use the new funds to build out some of those initiatives - like the RetireGuide feature, which syncs customers' accounts, including non-Betterment accounts, to help plan for retirement.

The firm, which currently has 149 employees, also plans to hire. Stein said he is looking to fill roles in engineering, design, product management, and investment management.

Betterment said it has grown from managing $1.1 billion to now nearly $4 billion in assets for more than 150,000 customers over the past 15 months.