Mark Ruffalo Joins Call for a Tax on Wall Street

The movement has drawn some support from financial circles. Wallace C. Turbeville, a former Goldman Sachs banker who now is a senior fellow at Demos, a public policy research organization in New York, submitted testimony last month for the Senate Banking Committee in favor of more banking regulation.

Mr. Turbeville, who oversaw an infrastructure and energy finance group at Goldman in London in the 1990s, said on Tuesday that a tax on financial transactions could serve a dual role, raising revenue for the government while reining in risky financial behavior. Such limits are especially important in the aftermath of JPMorgan Chase’s trading debacle, he said.

“A lot of activities in the financial services industry just can’t be regulated well by things like measuring what the potential consequences are and reserving against them, largely because they are very difficult to measure,” he said. “So limiting activities is actually quite essential.”