Stanford PhD dropouts under 30 making their mark in tech: What Carina Hong and Demi Guo share

Hong launched Axiom Math in March at age 24, and the startup has rapidly gained traction in the AI sector. It secured US$64 million in seed funding in September and has managed to recruit a team that includes former employees of major tech companies such as Meta and Google DeepMind, as well as a world-renowned mathematician, Ken Ono.

Meanwhile, Guo, now 27, founded AI short-video startup Pika in 2023. The company has since drawn global attention, reaching 16.4 million users across its creative apps as of October and raising about $135 million while valued at $470 million.

They each come from different backgrounds but share a number of common traits.

Demi Guo (left), co-founder of Pika, and Carina Hong, founder of Axiom Math. Photo from Demi Guo's X and Carina Hong's LinkedIn

Leaving Stanford PhD programs for business

Hong was pursuing a joint law degree and mathematics PhD at Stanford but left the program shortly after Axiom closed its seed funding round last summer.

She has described both mathematical research and her first year of law school as "very fun" and said that she often worked with more senior researchers during her years in academia.

Before Stanford, she earned a bachelor’s degree in mathematics and physics from the Massachusetts Institute of Technology, where she wrote nine research papers and completed 20 advanced mathematics courses, before going on to Oxford as a Rhodes scholar to study neuroscience and produce two dissertations.

Guo similarly left Stanford’s computer science PhD program to co-found Pika with fellow PhD student Chenlin Meng. Her work at Stanford, which centered on applying AI to content creation, and her frustrations while attempting to make a short film helped shape the idea behind the startup, Bloomberg reported.

After stepping away from their studies, the pair focused on building the company, releasing its first AI-powered video creation software in late 2023.

She also has a bachelor’s degree in mathematics and later a master’s in computer science from Harvard University.

Looking back on her education, Guo said: "Whether it’s Harvard, MIT, or Stanford, it’s not that important. What matters is your personal growth."

Hailing from China

Hong and Guo were both born in China, with Hong hailing from Guangzhou and Guo from Hangzhou.

They also displayed their talent early in life. Hong spent her childhood in Guangzhou and developed a passion for mathematics at a young age. She taught herself English in order to read advanced mathematics textbooks.

In high school, she was one of just four girls selected for her provincial mathematics Olympiad team and went on to perform strongly in competitions like the Hua Luogeng Cup and the National High School Mathematics League, according to Chinese media outlet 36Kr.

"I was always very interested in mathematical discoveries," she told The Wall Street Journal.

Her talent later earned her the Schafer Prize in 2022 and the Morgan Prize in 2023, making her the top undergraduate woman in mathematics.

Guo boasts a similarly remarkable academic record. She won a silver medal at the International Olympiad in Informatics in 2015. She also interned at major tech companies, including Microsoft and Google, during her time at Harvard.

"When I was young, I was good at writing and won many awards, but I wasn’t very good at maths," she once shared, as quoted by the South China Morning Post. "I thought being good at writing wasn’t cool enough, and since programming and maths were male-dominated fields, excelling in maths felt more challenging."

What sets their background apart is that Guo grew up in Silicon Valley and comes from a distinguished family: her mother is an MIT graduate while her father, Guo Huaqiang, was previously the chairman of Hangzhou-based IT services company Sunyard Technology.

Hong’s parents, meanwhile, come from a rural area of Chaoshan.

"My cousin and I are the only two in my large extended family who have/ will receive(d) college education," she wrote in a story for MIT Office of the First Year’s First Gen and/or Low Income Program.

Making Forbes’ 30 Under 30

Both women were featured on Forbes’ 30 Under 30 for the AI category.

Guo and her startup made the 2025 list, released late last year, while Hong was named among the 2026 cohort earlier this month.

With Axiom, Hong aims to develop what she describes as an "AI mathematician," a model that can tackle complex mathematical problems, produce detailed proofs of the steps needed to solve those problems, and check its own reasoning.

"Math is the perfect sandbox for building superintelligence," Hong told Forbes.

As for the vision behind Pika, Guo said: "We’re trying to build the best video model, but also trying to build a product that’s really serving creators."

The technology behind her startup sits at the center of broader debates over AI’s impact on creative industries like film and entertainment. But Guo has affirmed that Pika is not meant to replace human artists.

"The human artist is the one to guide AI in the right direction and eventually become a masterpiece," she said.