ABC's "This Week" host Martha Raddatz asked Sanders about Blackstone CEO Steve Schwarzman's argument that financial markets are unsettled because of Sanders, China's slowdown and global geopolitical risk.
As Sanders laughed, Raddatz pressed him on the impact a declining stock market has on retirement and pension funds.
"The reason that I am laughing is that I fully admit to having a big ego, like many other politicians," Sanders said. "But the idea that Bernie Sanders' candidacy, because that it has growing support all over this country, is unsettling world markets, is absolutely absurd."
Sanders said that he is, though, "getting the attention of Wall Street" with his calls to break up big banks and reinstitute a Depression-era law repealed under Bill Clinton that once separated commercial and investment banks.
"Wall Street's greed and recklessness and illegal behavior drove this economy into the worst recession since the Great Depression. Millions of people lost their homes, their life savings, and their jobs. And, yes, I believe that we have to break up the major financial institutions. We have to re-establish Glass-Stegall," Sanders said.
He added: "And that we are now gaining the attention of Wall Street tells me that our campaign is doing very well."
Sanders also brushed off the endorsements that Democratic rival Hillary Clinton has picked up in recent weeks -- including the support of the Des Moines Register, Iowa's biggest newspaper, just ahead of the state's February 1 caucuses.
Sanders said that's another sign of his campaign's success.
"We are taking on the entire establishment. We are taking on the economic establishment, we're taking on the political establishment, and all due respect, we are taking the media establishment," he said.
He also said that organizations that allow their members to vote on endorsements -- including MoveOn.org -- are actually supporting him.
"I expect that Secretary Clinton will get a lot of the endorsements from mainstream media, but I have the endorsement, and I'm very proud to say, of 2.5 million individual contributions to my campaign," Sanders said.