Arjuna Capital, an investment company based in Boston that focuses on sustainable and impact investing, says the big banks are in the Stone Age when it comes to issues of gender pay equity.

Arjuna forced pay equity investor votes at tech companies last year, and is taking on the big banks and credit card companies this year. The firm has filed resolutions with Bank of America, MasterCard, American Express, JP Morgan, Wells Fargo and Citigroup. The companies, with the exception of MasterCard, are opposing the resolutions.

The resolutions, if approved by investors, would require the banks to reveal whether there is a gender gap in their compensation structures and to take steps to correct it if there is. The resolution filings were announced Thursday during a web conference.

The firm forced resolution votes last year at eBay, Intel, Apple, Amazon, Expedia, Microsoft and Adobe. The firms revealed data on pay standards and, at the companies where gaps were found, steps are being taken to correct the situation, says Natasha Lamb, managing director and lead filer of gender pay resolutions at Arjuna Capital.

“Big tech stepped up in 2016 and took real action to address the legitimate concerns of long-term shareholders and women,” Lamb says. “Yet the banks are sticking their heads in the sand, which makes you wonder: What do they have to hide?”

The financial services industry is one of the biggest offenders when it comes to a lack of pay equity and transparency, Lamb says.

Companies that have equity in their hiring and pay practices are better retainers of talent, which boosts the bottom line for the firms, says Evelyn Murphy, the former lieutenant governor of Massachusetts  and founder and president of the WAGE Project Inc., a nationwide, grassroots activist organization dedicated to eliminating the gender wage gap.

“The median income for women working full time in the United States is reported to be 79 percent of that of their male counterparts,” Murphy says. “That $10,800 disparity can add up to nearly half a million dollars over a career. The gap for African-American and Latina women is even wider at 60 percent and 55 percent, respectively. At the current rate, women will not reach pay parity until 2059.”