Aspect Ventures is the name. And the most interesting aspect of this startup—besides the cofounders’ focus on mobile, which says a lot about where Silicon Valley money is flowing—is that their exits from their well-known firms means that there are now almost no female senior partners in Silicon Valley’s biggest VC firms.

A plan that germinated over a lunch at the Cantor Arts Center on Stanford University’s campus last September (“Why don’t we go into business together?” Fonstad recalls asking. “I said Yes instantly,” says Gouw) has Fonstad leaving Draper Fisher Jurvetson, where she’s the only female managing director, and Gouw departing Accel Partners, where she’s been a managing partner and the sole woman on an 18-person U.S. investment team. (Accel has a female partner, Sonali De Rycker, in London.)

Meanwhile, other major VC firms in the Valley such as Benchmark, Redpoint and Sequoia Capital have all-male teams investing their capital. Andreessen Horowitz has eight general partners — eight guys who make the investment decisions and take seats on the boards of the startups they fund. Kleiner Perkins has several female partners, but only life-sciences investor Beth Seidenberg and Mary Meeker, the renowned Internet analyst who left Morgan Stanley three years ago to lead Kleiner’s $1 billion digital growth fund, are general partners—the real power tier at the firm.

Fonstad and Gouw aim to change the ratio—by making Aspect Ventures one of the major VC firms in Silicon Valley. Focusing on seed and early stage investments in mobile computing, Gouw says, “We want to be the first institutional investment partner for entrepreneurs we work with.” The co-founders say they have enough money to do what they want to do in the next two years—that is, invest $500,000 to $3 million in each of 12 to 24 investments.

They’re funding their venture themselves—“100% founders capital,” says Gouw, adding that they anticipate inviting three to five general partners into the firm.

This is not two strangers teaming up on a crazy bet. “Theresia and I have known each other for 25 years,” says Fonstad. After college (Fonstad went to Georgetown and Gouw studied engineering at Brown), they worked on the same “case team” at Bain. Then, in 1996, Fonstad’s firm, Draper Fisher Jurvetson, invested in Ranzetta’s startup, Release Software. Three years later, after Fonstad joined DFJ and quickly made partner, Gouw wanted to test her own talents as a VC. “Jennifer was the first person I called,” she recalls.

They’ve co-invested a bit, but both women have strong track records on their own, making more than 80 seed and Series A investments that have led to six IPOs: NanoString , Trulia , Imperva , Athenahealth PeopleSupport , and NetZero . Athenahealth, which has a $5.2 billion stock-market value, is one of Fonstad’s investments and the biggest win.

While Gouw has backed a lot of women-led startups — Birchbox, LearnVest and ModCloth, to name three — Aspect Ventures will not be playing the gender game. That is, the firm won’t have a bias toward women-run companies. “But we do bring different perspective,” says Fonstad about women in business. “And there’s evidence that having women on boards does improve ROI.” Aspect will look to recruit female directors to the companies it funds, as well as add male partners to its own mix.

Asked whether their old firm’s male cultures frustrated them and led them to go solo (or duo, in this case) Fonstad admits that her industry’s culture has been challenging at times — and she can’t help but bring the best-selling Lean In by her famous friend at Facebook . “Sheryl Sandberg talks about the penalties women take for being aggressive and tough,” says Fonstad, 48. “I’ve experienced some of that.”

“We’ve both worked at great places,” adds Gouw, 45. “It’s not so much about running from a place as running to a place.”

If these two women succeed, becoming role models will be a payoff beyond any hefty ROI. “By being more visible and showing we can do this,” Gouw says, “maybe women will become more confident to be entrepreneurs and investors themselves.”