The exchange is still in the early stages of development. Co-founders Jethi and Campanale are researching demand for it, with a $500,000 grant from the Rockefeller Foundation. They are going to need approval from the Financial Services Authority (the U.K. equivalent of the Securities and Exchange Commission), a process that, according to Jethi, could take a year. Once all that’s squared away, they have to arrange with an existing stock exchange to lease a trading platform.

But already, says Jethi, they’ve identified about 1,200 of the 55,000 social enterprises in the United Kingdom as candidates for listing on the exchange (only 12, he says, are needed to launch the exchange.)

One such company is a 10-year old firm called Ethical Property Co. It buys buildings, then rents space to social-change organizations, offering low rent and access to technology and other shared resources. It’s also a public limited company, a type of business in the United Kingdom that’s public but not listed. Ethical Property has about 1,500 investors, who put anywhere from 100 to 1 million British pounds into the company. Founder Jamie Hartzell says that he never considered a conventional listing, because “we’d lose control over our mission.” Clearly, a social exchange would be right up his alley.

All Together Now

The effort to form a social stock exchange in the United Kingdom is sparked by a climate that’s considerably friendlier to social enterprises than in the United States. The U.K. Office of the Third Sector is now engaged in developing a social investment bank, a wholesale institution that would lend to retail banks working with social enterprises. Also, the government in 2005 introduced something called the "community interest company," a legal structure for social enterprises so they can establish themselves as companies while ensuring that their profits or assets be reinvested in a way that supports their mission.

Added to this mix in the United Kingdom are a slew of charities, foundations and venture capital firms involved in impact investing.

There’s even a company offering a new twist on portfolio management. Investing for Good, a four-year-old company, is pioneering a way to make it easier for private banks and wealth managers to invest clients’ money in social ventures. “The mission is to embed social investing in mainstream financial portfolio management,” says Investing for Good’s CEO and founder Geoff Burnand, who worked as a financial advisor at Merrill Lynch for 15 years.

Burnand creates customized portfolios comprised of private, socially responsible ventures that fit each client’s needs, drawing from a group of about 230 heavily researched businesses and funds. For advisors with a client interested in affordable housing, for example, he’ll put together a portfolio emphasizing companies involved in that type of work. He’s also coming out with a blended social impact fund this year.

But that’s just one more reason for advisors to be conversant in the world of British-style social investing—before their clients start asking about it.