What really worries the industry, according to the candidate, is that Americans will come together to fight for change. “They’re starting to think, ‘Could this really happen?’” Sanders told an audience of 1,100 last month in Sioux City, Iowa. “We are their worst nightmare.”

Just not quite for everyone.

“There’s another crowd of us on Wall Street who are far more understanding,” said Dan Alpert, founding managing partner at investment bank Westwood Capital in New York.

The widening gap between rich and poor “is not commensurate with a free society and democracy, and eventually you’re going to have people with pitchforks.”

While Sanders has been gaining in polls in key states such as Iowa, New Hampshire and California -- in some cases building significant leads -- the national frontrunner appears to be Vice President Joe Biden. The most recent polling average from RealClearPolitics has Biden in first place with 27.2%, followed by Sanders at 23.5% and Massachusetts Senator Elizabeth Warren at 15%. Iowa’s results could soon shake that up.

Warren also has won surprising support from a small group of Democratic-leaning financiers. Some of them like the redistributive policy proposals she and Sanders have advanced and predict the measures would help -- not hurt -- the economy in the long term.

Of the $96 million raised for Sanders through last year, $1.6 million came from the finance, insurance and real estate industries, according to the Center for Responsive Politics. That compares with $4 million for President Donald Trump from the same sectors.

Cornell University law professor Robert Hockett said that after he gives media interviews in support of Sanders, he gets private messages of encouragement from finance-industry friends, agreeing that health-care access and income inequality need to be addressed.

“I’m not alone,” said Hockett, who previously worked at the Federal Reserve Bank of New York and International Monetary Fund and has done policy work with both campaigns. His contacts on Wall Street “have to be a little bit more careful because they might get fired or earn the hostility of their colleagues,” he said.

Calvin Tse, a senior currency strategist at Citigroup Inc., surveyed market participants last month and concluded they are underestimating the risk of a Sanders victory.