Having more women participate on company boards may be a lucrative strategy for investors.

Richard Kersley and his team at Credit Suisse examined the impact of female representation on boards of directors, and they published their findings in a 2014 report. They reviewed 3,000 companies and found that companies with women on the board outperformed those without women.  

Specifically, large companies — those with market caps over $10 billion market cap — with at least one woman on the board outperformed those without any by 26% over the six years ending December 2011.

And that momentum persisted beyond that initial measurement period.

“From the start of 2012 to June 2014, we have seen 5% outperformance on a sector neutral basis by those companies with at least one woman on board,” they wrote.

The analysts found the divergence was even more pronounced when they measured boards with above-average concentrations of women versus those that were below average. Large global companies above the average outperformed those below by 36% (or 3.7% per year) from 2005 through the first half of 2014.

Additional research has shown that more women on boards and in senior management can also increase profitability. The Peterson Institute for International Economics and Ernst & Young LLP released a study earlier this year looking at over 20,000 publicly traded companies globally and found that those with 30% female directors and executives added as much as 6 percentage points in net margins.

Activist investors have taken heat for the underrepresentation of women they nominate to corporate boards. On this International Women’s Day 2016, with female representation on corporate boards standing at around 13%, investors may want to think about being more aggressive of about increasing gender diversity.