Fong said investors wanted it too. "They want to give back - especially our women investors."
The shortfall for women was driven by unconscious bias, with overseas studies showing women entrepreneurs pitching for money were often asked prevention and negative questions such as how they would prevent their business from failing.
Male entrepreneurs tended to be asked promotional questions such as how they would grow the business or what their milestones were for 10 years' time.
"So they have always struggled to get funding and that is why these barriers exist," Fong said.
"We are trying to break down these barriers, provide more awareness and inject $10m to $20m into the eco-system to foster this community."
The fund had raised $5m since January and hoped to have the full $20m sometime this year.
Fong said there was no shortage of women-led or women-founded businesses to invest in.
"They are referred to me on a weekly basis. There are so many people taking that step and embarking on that journey into entrepreneurship and so I'm really confident we are going to have a group of companies we are looking at all the time."
The fund had already invested in online pet food delivery company Feed My Furbaby and two others were on the way.
Fong said investors typically came via the Icehouse Ventures network of more than 2000 investors.
"We are constantly networking, connecting and growing our community here and overseas."
Some investment came from Australia and others around the world who had a passion for supporting women also supported the fund.
The fund is the second of its type, focused on investing in women-led companies. The first raised $2.8m two years ago and has invested in 31 start-ups including Hnry, Easy Crypto, ArchiPro and Astrix Astronautics.
Gattung, who is also the New Zealand country lead of the global women entrepreneur initiative SheEO, said she intended to keep giving her time, energy and money to backing women entrepreneurs.
"Early-stage ventures are receiving more funding than ever before and yet the amount of money going to women raising capital in this country is tiny," Gattung said.
"This needs to change, and it is exciting to back women entrepreneurs and investor groups like ArcAngels who are growing angel investor networks to support women-led businesses.
"I believe New Zealand has the opportunity to stand out and make a difference if we all work together."