The field of social entrepreneurship advances apace, and this week was no exception. In fact, for those who champion business and the capital markets that fuel those enterprises as a critical engine of social change, we may have reached an “impact” watershed.

On Tuesday, the New York Times reported that Former Governor of Massachusetts Deval Patrick, who helped pioneer pay-for-success financing in the United States, had joined Bain Capital to lead its nascent impact-investing fund. This news followed the recent announcement by BlackRock, a global investment firm with more than $4 trillion in assets under management, that it had launched BlackRock Impact, a platform to meet client demand for investments that are profitable, and socially and environmentally responsible. Indeed evidence of client demand, particularly from women and millennials (who represent increasingly powerful segments of the investor base) is emerging loud and clear. Bain and BlackRock join the ranks of Morgan Stanley, Bank of America, Goldman Sachs, Citi, JP Morgan Chase, UBS, HSBC, and other major financial service firms, in devoting units or entire businesses to “social impact” or “sustainable investing.” This is not philanthropy, but rather a determination that the generation of social or environmental value alongside financial returns has a strong business case.

Helping make that case are the growing number of companies that view sustainability as central to their long-term profitability. On Wednesday, the Brooklyn-based, on-line marketplace and certified B Corp Etsy filed for an initial public offering, and shone a bright and precedent-setting light on the fusion of values and value. Securities and Exchange Commission filings are not typically page-turners, but Etsy’s is worth a read, as it declared to the world and potential investors: “We believe that business interests and social and environmental responsibility are interwoven and aligned, and that the power of business should be used to strengthen communities and empower people.” Etsy matters for many reasons, among them is that it’s only the second of 1,200 B Corps to go public (the first was Rally software), testing its commitment to a broad set of stakeholders—including employees, the community, and the environment—in the public markets.

B Lab, the nonprofit behind the B Corp movement, marked another important milestone this week with the formal launch of B Lab UK. Recently, B Lab has turned to campaigns like Measure What Matters to encourage all companies, not just prospective B Corps, to consider the social and environmental impact of their policies and practices. Today, 20,000 businesses are using versions of B Lab’s impact assessment to measure their social and environmental impact.  B Lab has also helped to pass benefit corporation legislation in 26 states, which removes legal and fiduciary barriers for entrepreneurs and investors to scale social purpose businesses.

On Friday, David Blood, the co-founder of Generation Investment Management, addressed these issues head-on in his keynote at the Morgan Stanley Sustainable Investing Challenge. “Our point of view,” said Blood, “is that if you don’t consider ESG [environmental, social, and corporate governance], you are not fully fulfilling your fiduciary responsibility.” In a wide-ranging conversation with Equilibrium Capital’s David Chen, Blood went on to explain Generation’s investment thesis: Sustainability, which takes into account the risks of things like climate change, is the smart way to manage a business for the long term and a lens to make better investment decisions.

Making use of that lens were the eight finalists teams in the challenge, narrowed from submissions from 380 graduate students from 78 schools across 20 countries. Unlike most business plan competitions focused on social enterprise, this one, co-sponsored by Kellogg and INSEAD business schools, requires that students propose investment vehicles that seek positive environmental or social impact alongside competitive financial returns. Entries showcased a range of financial solutions to support sustainability, economic development, and human well-being—including flood mitigation, distributed energy services, displaced persons resettlement, and controlled environmental agriculture in countries all over the world. The winner, Blue Forest, from the Haas School of Business, proposed conservation notes designed to alleviate drought and reduce forest fires through improved forest management, using a pay-for-success financing structure.

Each of these developments represents an important evolution in the impact field—what Elizabeth Littlefield, president and CEO of the Overseas Private Investment Corporation, calls the social impact investment “ecosystem.” During a Skoll World Forum panel on innovative finance and inclusive business last Thursday, Littlefield noted a “disconnect” in perspectives: Social enterprises, she explained, claim that there is not enough capital to go around, while investors cite insufficient deal flow. What we need, she said, is to improve the “infrastructure”—a kind of “better plumbing”—to advance the sector. This was indeed a profitable week for impact plumbing—and critical for channeling the groundswell.