(A fan crowd-surfs at the Lollapalooza music festival in Grant Park in Chicago.Reuters/Jim Young)

• Millennials are driving the nearly $9 trillion sustainable investing market, according to a survey of 1,000 investors by Morgan Stanley's Institute for Sustainable Investing.

• Despite recent strides in the space, the belief that sustainable investing solutions deliver weaker returns remains prevalent.

Millennials aren't just eating avocado toast and snapchatting; they're also driving the growth of a $9 trillion market on Wall Street: sustainable investing.

Sustainable investment products, which aim to deliver outsize returns and remedy societal and environmental ills, have grown at a rate of more than 33% between 2014 and 2016 in the US, according to data from the US SIF Foundation cited in a newly released report by Morgan Stanley. The market for such products, as a result, has grown from $6.57 trillion to $8.72 trillion.

Morgan Stanley's "Sustainable Signals" report, a sequel to a 2015 report on the subject conducted by the bank's Institute for Sustainable Investing, examines the findings of an impact-investing-focused survey of 1,000 active investors across the age spectrum. It found that millennials have underpinned the growth of the market for impact investing and the adoption of sustainable portfolio options and other products such as green bonds and green ETFs.

Millennials "are twice as likely as the overall pool to invest in companies or funds that target social or environmental outcomes," the report said.

Millennial interest has grown since 2015. From 2015 to 2017, interest in sustainable investing grew from 84% to 86%, while those who said they were very interested in impact investing grew by 10 percentage points, to 38%.

(Millennials' interest in impact investing leads the general populace.Morgan Stanley)

According to the report, the rise of interest in sustainable investing stems from sustainable behavior in the consumer space. Furthermore, millennials are twice as likely to buy goods from sustainable companies than the total population. This behavior has been bleeding into financial services, according to Audrey Choi, chief sustainability officer and chief marketing officer at Morgan Stanley.

“As widespread attention to sustainability continues to increase, consumers and investors alike are now more than ever factoring sustainability issues into their investment decisions,” she said in a press release emailed to Business Insider.

"What we are seeing right now is just the tip of the iceberg," Amit Bouri, cofounder and chief executive officer of the Global Impact Investing Network, told Business Insider. "In the coming years, budding interest will translate into more and more concrete action on the part of financial-services firms."