Is sustainable investing just a millennial gimmick, or a valuable new model for investment? With its Redwood Fund, the new banking service Aspiration is betting on the latter.

Aspiration, which calls itself a “socially conscious” banking service, tailors its products to the more discerning eye of millennial consumers, who may watch which companies are receiving their money more closely than some previous generations.

Take its Redwood Fund, for instance, which launched in 2015: the fund focuses on “sustainable” investing, meaning the companies within it are carefully screened with respect to their environmental, workplace, and governance practices.

That means the companies are examined for how they approach problems like diversity and energy use, among other factors. Users can view the companies included in the fund in three categories: environmental, social, and governance.

So far in the fund’s short life, that approach seems to be working out well for investors.

“Over the past year, the Redwood Fund has been in the top 1% to 2% in terms of performance, for all large top [cap] funds,” Andrei Cherny, CEO at Aspiration, told Bank Innovation, a figure supported by Bloomberg and Morningstar, among others.

In addition to the “sustainable” nature of the fund, it also has a low investment minimum of $100 to further draw younger and even first-time investors. Cherny added the fund is adding “many thousands” of customers per week, the majority of which are millennial investors.

“The average customer is under 35, but most importantly, the majority are people who have never made an investment before,” said Cherny. “There’s been low-cost investment funds before, there’s even been low-minimum funds, but we’ve found that a lot of people don’t feel like they don’t have a financial partner when they invest.”

Another factor that might explain the fund’s millennial popularity is its approach to fees: the fund has a “pay what is fair” model, which means Aspiration and its portfolio managers only make what the customer decides they will pay.

Aspiration’s Redwood Fund is tracked under REDWX, right now, the fund is up .33%, and up 22.34% in the last year, according to the company.  Currently, it’s total assets measure $31.3 million, according to Morningstar.