The New York Stock Exchange has appointed a new leader – a woman.
Cunningham landed her first full-time job on Wall Street in 1996 as NYSE Floor Clerk with JJC Specialist, a division of Quick & Reilly. From there, she worked her way up to her current position as Chief Operating Officer.
"Stacey was born to run the New York Stock Exchange and she will do a fabulous job," said Grasso.
Even if Cunningham has decided to run the show, few women find themselves on the floor of the stock exchange – or on Wall Street.
According to Catalyst, a non-profit organization committed to inclusive jobs for women, women hold only 4.6 percent of CEO positions in S & P 500 companies. Of the Fortune 500 companies, 12 do not have a single female board member.
While Cunningham called the stock market "home" and said she liked being part of it, she acknowledged that very few women work in finance and technology.
"It's a male-dominated environment," she said Tuesday on "Squawk on the Street." "And that has not changed quite as fast as some other industries."
In fact, the speed of this change was "glacial," said Janice Ellig, CEO of the executive search firm Ellig Group.
Ellig pointed out that in 1995, when Catalyst began tracking women on company boards, Catalyst accounted for about 9 percent. Today it is closer to 21 percent.
"That's less than 1 percent a year over a 20-year period," Ellig said on Tuesday's "Power Lunch."
And gender diversity reaches beyond the employees, Ellig said. It should include shareholders, consumers and members of the community in which a company operates.
"All indicators show that women make a difference," said Ellig. "Why should not a company use this talent?"
Businesses need to pay more attention to women in the ranks and throughout their careers, she said.
"You have to be careful to develop different candidates and build this pipeline so you can promote it," Ellig said.