In the three years since Phoebe Gates and Sophia Kianni first asked the question “how can we make secondhand shopping easier?”, they’ve brought on investors like Kris Jenner, Sara Blakely and Hailey Bieber.
Phoebe Gates (left) and Sophia Kianni (right)
courtesy of Phia
When Phoebe Gates and Sophia Kianni founded AI shopping platform Phia from their Stanford dormroom, they knew it was only a matter of time before investor talks began. In the three years since first asking themselves the question “how can we make secondhand shopping easier?”, they’ve brought on investors like Kris Jenner, Sara Blakely and Hailey Bieber.
This week, they added another check to the list: A $35 million Series A led by Notable Capital, nearly five-times the size of their $8 million seed round last spring. The startup now counts more than $43 million in total funding at a $185 million valuation, and more than one million users.
“We are sitting on top of a trillion-dollar opportunity being the agent that determines what women buy,” Gates, the daughter of Bill Gates and Melinda French Gates, tells Forbes. “We wanted to have the capital, frankly, to be able to incentivize the best talent in the game.”
Today the shopping platform uses AI models to compare an item a user is shopping for online with hundreds of millions of products—to find the most accurate match at the best price, including some secondhand options. To offer the service, Phia is building an in-house search engine (available on both desktop and as an iOS app) with the help of top talent like eBay and Pinterest alumni. This new funding will help hire more engineers to work on machine learning infrastructure, sourcing models and user personalization tools.
So how does it work? When a user is online shopping, Phia can detect the exact image by price, brand, and physical attributes like color and shape. Those data points then go through a unification process where AI compares the item to more than 300 million others in Phia’s database to identify the best seller. But Phia also pays attention to what each user typically searches for.
Paula Lobo/Getty Images for Gates Archive
“A lot of this is contingent on this idea of personalization and being able to really attune all of our results to your own personal behavior and your own personal taste, style and preferences,” Kianni says. “That’s where the data does become very complicated and why it’s important to have people who are senior and experienced in this domain.”
Phia began as a browser extension that surfed the web for resale comps to items shoppers were searching. It didn’t work well, Gates says. “But the fact that people were still interested, even though it was a horrific product at that time, meant that we were onto something.”
They got more than an A on the project: Their first check came in the form of a $250,000 grant from the professor who assigned them the task in the first place. They then took part in the Soma fellowship (a program that’s backed more than two dozen unicorns like Deel, Cognition, Kalshi and Mercor, to name a few). By April 2025, Gates and Kianni pivoted to build an iOS app, and brought on heavyweights like Kleiner Perkins and Michael Rubin, among others. Much of these early investors were inbound, Gates and Kianni say.
“It’s very important, in my opinion, for founders to publicly share their wins,” Kianni says. “We got a ton of investors who reached out to us solely because we were posting on LinkedIn and publicly talking about the user growth and the revenue growth that we were seeing. Of course, that piqued the investor interest.”
In the early days, projections and initial proof of concept did a lot of the talking. But in this Series A, “data is king,” the cofounders agree. So while many of their investor relationships began conversationally, finding a way to clearly communicate the company’s metrics is what pushed their deals over the line. For Phia, that meant explicitly outlining their distribution power (like hundreds of millions of views on social media platforms), near-zero customer acquisition costs, and laying out a clear revenue model in the form of pitch decks and Notion boards.
“The later stage that you get as a company and the further you are in your funding journey, the more this is very much a data-oriented process,” Gates says. While the goal with those smaller, earlier rounds was to prove product-market fit, now conversations surround the company’s unicorn potential. “As your business grows and matures, you [must be] able to distill everything into a simple business model and financial model to understand how it can become a multi-billion dollar business.”
Look back on the week that was with hand-picked articles from Australia and around the world. Sign up to the Forbes Australia newsletter here or become a member here.
