A $2.5 trillion asset manager just put a statue of a defiant girl in front of the Wall Street bull

The world's third largest asset manager just installed a bronze statue of a defiant girl in front of Wall Street's iconic charging bull as part of its new campaign to pressure companies to add more women to their boards.

State Street Global Advisors, a nearly $2.5 trillion investor and unit within State Street Corp., is rolling out the campaign ahead of International Women's Day on March 8.

The huge money manager said it will vote against boards if a company fails to take steps to increase its female membership. The company plans to send out a letter to 3,500 companies on Tuesday asking the companies to take action.

State Street is a huge player in the index fund world, managing about 90% of its assets in passive funds, which are often investing in companies held in the Russell 3000 and FTSE.

The money manager has cited gender diversity as a way to improve company performance and increase shareholder value. Lack of women on boards has long been a problem. Beyond pipeline issues, some boards see no reason to increase gender diversity, data shows.

"There has been a lot of discussion on this topic, but the needle hasn't moved materially," Lori Heinel, the firm's deputy global chief investment officer, told Business Insider on Tuesday after the statue installment.

For State Street, the statue was a way to draw attention to the issue. Currently nearly a quarter of boards represented in the Russell 3000 have no women at all, Heinel said, citing Institutional Shareholder Services data.

"One of the most iconic images on Wall Street is the charging bull. So the idea of having a female sort of stand against the bull, or stand up to the bull, just struck us as a very clever but also creative and engaging way to make that statement," Heinel said. "Even though it's a little girl, her stance is one of determination, forwardness and being willing to challenge and take on the status quo."

Earlier on Tuesday morning underneath a light rain, passersby and tourists snapped photos in front of the newcomer. One young man who said he worked in the area described the statue as "cool."

SSGA installed the statue in collaboration with city officials earlier in the morning, and expects the statue to stay in place for up to a month, a company spokesman said.