Over the past decade, Republican vice presidential nominee Sen. JD Vance of Ohio has quietly built a network of allies on Wall Street, one that is distinct from his running mate, former President Donald Trump's, circles.

Now, Vance's fans are mobilizing to help him raise millions of dollars for the Trump-Vance presidential campaign.

On Thursday, Vance will headline two fundraisers in New York City hosted by some of his top supporters in the financial industry. Each of the events is expected to raise more than $1 million for Donald Trump's presidential campaign operation.

First up is a $10,000-a-plate-minimum breakfast co-hosted by investor Scott Bessent, Morgan Stanley's Jonathan Burkan, Cantor Fitzgerald CEO Howard Lutnick and Norm Champ, a former director of the investment management division at the Securities and Exchange Commission. Couples must donate $50,000 to attend.

Later in the day, investor Keith Rabois, Palantir advisor Jacob Helberg and Burkan are among the co-hosts for a Trump campaign lunch, according to an invitation. Tickets range from $25,000 per person to $250,000 per couple.

"J.D. Vance has shown a strong commitment to advocating for policies that strengthen American workers and businesses," Champ told CNBC. "His focus on economic revitalization and creating opportunities for growth aligns with values that many, including myself, support."

Champ added, "looking ahead, I plan to continue supporting leaders like Vance who prioritize the needs of the American people."

Another notable Vance supporter is Sander Gerber, the CEO of investment firm Hudson Bay Capital.

The two men met for the first time in New York during the 2022 midterm elections, when Vance mounted a successful Senate campaign in Ohio.

Gerber told CNBC he was impressed by the Ohio Republican's story of overcoming a difficult childhood, the subject of Vance's 2016 memoir, "Hillbilly Elegy" and a Netflix biopic released in 2020.

Gerber also said he was open to potentially hosting a campaign fundraiser headlined by Vance later this fall.

"I'm a big fan of JD, and I'll do anything I can to help him," he added.

One of Vance's earliest interactions with Wall Street came shortly after the November 2016 presidential election, when he headlined a lunch in New York to discuss his newly published memoir.

Among the attendees were several senior figures at Goldman Sachs, according to a former executive there. This person, like some others in this story, were granted anonymity in order to speak on private matters.

The following year, Vance attended the famed Allen & Company business conference in Sun Valley, Idaho, where he rubbed elbows with leaders from a wide range of industries, including Wall Street.The connections Vance developed paid off when he decided to run for the Senate seat of retiring Ohio Republican Sen. Rob Portman.

John Underwood, a longtime managing director at Goldman Sachs, encouraged his allies to support and raise money for Vance's Senate campaign, according to people familiar with the matter.

Underwood initially got to know Vance after "Hillbilly Elegy" was published, according to a person familiar with their relationship. Vance later participated in a Goldman Sachs fireside chat in Washington for some of the bank's clients, where he discussed his book.

Steve Case, a co-founder of AOL and CEO of investment firm Revolution, also took part in the discussion, this person explained. Vance worked at Revolution for about a year, and left in 2019. The fireside chat took place some time after Vance had already left the firm, the person added, although the precise date was unclear.

When Vance mounted a Senate campaign in 2022, he raised more money from donors in the securities and exchange industry than from any other professional industry, more than $650,000 according to OpenSecrets. Vance won the race by six points.

Ever since Trump tapped Vance to be his running mate in July, Underwood has been fielding inquiries from business leaders who want to know more about the junior senator from Ohio who could become vice president, some of the people involved told CNBC.

Underwood speaks admirably about Vance and pitches him as a strong choice to be Trump's running mate, a person familiar with the the calls said.

Some of the other financiers who have helped Vance raise campaign cash, both for his Senate run and the Trump political operation, include 1789 Capital president Omeed Malik and Emil Henry, the CEO of private equity giant Tiger Infrastructure Partners, according to people briefed on the matter and OpenSecrets data.

Henry is a former assistant Treasury secretary in the Bush administration, and he was among the guests at an Aug. 25 fundraiser for the Trump campaign where Vance was the guest of honor.

Bessent and investor Ted Virtue were also at the event, which was held at the palatial house of New York Jets owner Woody Johnson, two attendees told CNBC. Top tickets went for $50,000, and even with a limited guest list the event raised over $1 million, one of the attendees said.

A second Aug. 25 Hamptons fundraiser with Vance was held at the home of Clifford Sobel, managing partner of Valor Capital Group.

One attendee, the real estate executive and billionaire Richard Kurtz, said Vance spoke before a crowd of about 100 people. He told them the Trump campaign would need "hundreds of millions of dollars" to compete with Vice President Kamala Harris' fundraising surge.

Vance meant what he said. The Harris political operation recently announced that it raised $361 million in August, more than double the $130 million Trump's team raised last month.

The second Hamptons fundraiser was co-hosted by a group of financial executives that included Malik, veteran investor John Paulson and Reuben Jeffery III, formerly the president of asset management firm Rockefeller & Co., according to an invitation. Tickets went up to $50,000.

A small but loyal base of support for Vance on Wall Street has grown over the years, in spite of Vance's criticism of the financial industry, according to interviews with over half a dozen people familiar with the matter.

The Ohio Republican's opposition to Wall Street was on full display during the Republican National Convention in Milwaukee in July.

"Wall Street barons crashed the economy and American builders went out of business," Vance said in his nomination acceptance speech. "We're done, ladies and gentlemen, catering to Wall Street. We'll commit to the working man."

A spokesman for Vance did not return a request for comment for comment.

In Washington, Vance is seen as one of the more populist members of the Senate Banking Committee. He has also joined Democrats to back stricter accountability for bank leaders, including a bill to give federal regulators the authority to claw back bank executives' pay if their financial institutions fail.

Vance's previous backing of Federal Trade Commission chair Lina Khan's antitrust crackdown and stricter rules on mergers hasn't pushed everyone on Wall Street away from him.

"I'm with JD and I like [Khan] stopping M&A activity," said one longtime investor in smaller companies, who requested anonymity. "We're about innovation, and I want my companies to succeed."

Gerber, of Hudson Bay Capital, said he agrees with Vance that there needs to be more regulation on the banking sector.

"Some things have too much regulation. Some things have not enough regulation. I think there is a need now for a transformation of the banking sector," said Gerber.

Kurtz said Vance's criticism of the banking sector doesn't phase him. "There are problems with every industry, including Wall Street," he said.