Two-thirds of tech workers in Silicon Valley are foreign born, according to the 2025 Silicon Valley Index produced by Joint Venture Silicon Valley. Half come from Asia with India (23 percent) and China (18 percent) the most common countries of origin. Only 17 percent were born in California, and 14 percent from other U.S. states. (Quite a few of the American born are the children of immigrants from Asia.)

Forty-one percent of Silicon Valley residents are immigrants, Joint Venture reports.
Berkeley and Stanford "draw foreign college students to study science, technology, engineering and math, many with an eye to getting jobs in the valley after graduation," reports Ethan Baron for the Bay Area News Group.
However, Bay Area universities can't keep up with the demand for science and engineering graduates, says Sean Randolph, senior director of the Economic Institute at the Bay Area Council, which represents high-tech companies.
“If you look at the quality of educational programs in California or the United States, the skills level of people coming out of high school just in math, it’s not there,” Randolph said.
About one-third of California students test as "advanced" or "proficient" in math and science, giving them a shot at success in STEM majors.