State Street Global Investors’ SPDR SSGA Gender Diversity Index ETF (NYSE: SHE) has grown to $281.7m in assets since its launch on International Women’s Day on 8 March 2016, making it one of the most successful ETF launches of the year so far.

The SPDR SSGA Gender Diversity Index ETF (NYSE: SHE) has proven popular, having pulled in more $280m in assets since its launch on 8 March.

SHE has also returned more than 10% in US dollar terms since inception, not far off the broader S&P 500 Index’s 11.5% return in the same period.

“I was actually a little bit surprised that one of the big early launches was the gender diversity ETF, SHE, and it actually pulled a decent amount of money right out of the gate,” said Dave Nadig, director of exchange-traded funds at FactSet Research, during an ETF.com podcast.

A 2015 MSCI study on gender-diverse corporate boards between December 2009 and August 2015 found that companies with at least three female board members outperformed others in overall return on equity by more than 36%.

The underlying SSGA Gender Diversity Index replicates the performance of the highest ranked companies, by their ratio of women in the top tiers, across 10 sectors whose combined sector market capitalization equals 10%. The index currently comprises 187 stocks, each with at least one woman on its board or as CEO. The index is rebalanced annually on the last business day in June.

As of 9 September 2016 the fund’s largest sector allocations were healthcare (20.5%), information technology (15.4%), industrials (13.1%), consumer staples (12.4%) and consumer discretionary (12.3%). The largest holdings were Pfizer (7.0%), PepsiCo (5.0%), Amgen (4.2%) and 3M Company (3.4%).

Speaking to ETF Strategy, David Mazza, head of ETF and mutual fund research at SSGA, said: “Although this may be a small sample size, performance has illustrated that having a bias toward firms with more diverse leadership has led to higher returns with less drawdown in 2016—the same year that Hillary Clinton became the first female presidential nominee of a major US political party and Theresa May emerged as the top political leader in the United Kingdom following the Brexit referendum.”

Companies within the index posted average revenue growth of 2.70% compared with 0.45% for the S&P 500 Index over the last year, according to SSGA data. These firms have also grown their earnings-per-share by an average of almost 16% in the past five calendar quarters while S&P 500 constituents have seen earnings drop an average of 4.5%.

While SHE has enjoyed the most significant demand from investors, it is not the first ETF to base its investment selection on specific workplace equality practices. The $11.6m Alps Workplace Equality Portfolio Fund (NYSE: EQLT) tracks US companies that support equality for LGBT employees. It launched in February 2014 and costs 0.75%. Another product is the $30.7m Barclays Women In Leadership ETN (NYSE ARCA: WIL), which came to market in July 2014 and costs 0.45%. WIL specifies that companies must either have a female CEO or 25% women on the board of directors.

Both EQLT and WIL have generated positive returns in a bull market, but neither has raised the same assets or offered low fees like SHE, which costs just 0.20%.

SHE, along with EQLT and WIL, are positioned as specialist niche products within the larger and fast-growing Environmental, Social And Governance (ESG) space. The lion’s share of ESG ETF assets are currently held by two iShares funds in the US – the iShares MSCI USA ESG Select ETF (NYSE ARCA: KLD) and the iShares MSCI KLD 400 Social ETF (NYSE ARCA: DSI) – which both track liquid US companies and cost 0.50% in fees.

Although KLD launched in 2005, it has only grown to $426m in assets – less than double that of SHE, which came to market six months ago.

Fast fund-raising is a sign that investors are warming up to the concept of lining their portfolios alongside their personal values.

True to its name, SHE is co-managed by a woman, Lynn Blake. The ETF also donates a proportion of revenue to charity, via the SHE Gives Back fund, in order to tackle sexism and encourage girls from an early age to study science, technology, engineering and maths, and become world leaders.

Going forward, inflows and positive performance could be less certain for SHE, and the US equity rally in general, as we near the US election on 8 November – when the first woman president could be elected – as the race between Donald Trump and Hillary Clinton is tight and markets tend to be more turbulent in the autumn.