There is no doubt that impact investing as a concept has gone mainstream. This is no longer an idea that is being discussed at industry-insider conferences, in the halls of highly selective academic institutions and behind closed doors of executive suites. Everyone is talking about impact investing now, and everyone seems to be interested.

For those of us who have been passionate about impact investing for many years, the current level of discourse about this exciting new concept is truly a dream come true. It is deeply validating and encouraging to see this surge in interest and enthusiasm. More importantly, the space is brimming with optimism and hope, both for the concept itself and for all the great things that it can and should contribute to making the world a better place.

But the big question now becomes: How do we scale impact investing?

Currently, there are three key approaches under consideration.

1. Scale impact investing by expanding its popularity among high-net-worth individuals and family offices.

Historically, this segment has demonstrated particularly strong interest in impact investing, and some believe that capitalizing on this interest is the smartest way forward. In particular, according to a recent impact investor survey published by J.P. Morgan and the Global Impact Investing Network (GIIN), out of the $60 billion in impact investments to date, 73 percent are in the form of private equity or private debt. The same study indicates that 74 percent of impact investments are made directly into companies, and that over half of investors use referrals and word of mouth to identify promising companies in which to invest. These patterns reflect a market that is highly bespoke and where affluent individuals and family offices actively engage in making impact investments.

2. Scale impact investing by expanding its reach to include retail investors.

Many believe that this strategy will explode as millennials of all stripes start making investments over the next few years. According to a recent study by Morgan Stanley, 84 percent of millennial investors are interested in sustainable/impact investing. In particular, compared with all investors, millennials are nearly twice as likely to make investments that target specific social and environmental outcomes. Though the retail market for impact investments is still in its infancy, we are starting to see some innovative examples. For instance, Calvert Foundation offers a range of community investment notes, which enable retail investors to direct their capital toward issues such as inner-city development, women’s empowerment and education.

3. Scale impact investing by bringing institutional investors into the space.

Institutional investments are an area that many impact investing experts have been exploring in recent years. However, the overarching challenge that they’ve faced is the fact that impact investments are traditionally perceived as small, complex and highly risky. As such, they seem less appealing to institutional investors compared to environmental, social and governance (ESG) integration, for example. That said, some creative concepts are starting to emerge as sophisticated portfolio managers from large financial institutions begin to enter the space and brainstorm innovative product structures.

It is likely that all three of these approaches will take off over the next five to 10 years, as demand for impact investments grows and different types of organizations take part in the innovative process that’s underway. But as we rush to scale impact investing, the quality of investment products and sincerity of the impact intent will be key. This is a once-in-a-lifetime opportunity to develop something truly transformational. Let’s not waste it.