Net Worth: $15 billion

LAST YEAR: $12 billion
CHANGE: 25%
AGE: 83
RESIDENCE: Rolling Hills
SOURCE OF WEALTH: Technology

Tu in 1987 co-founded and today retains a 50% stake in Kingston Technology Corp. The Fountain Valley-based computer equipment company made itself a household name in hard drives and other computer memory modules like flash drives. Tu and cofounder David Sun sold 80% of Kingston to Japan’s SoftBank for $1.5 billion in 1996, only to repurchase the company for “just” $450 million in 1999. Throughout the past decade in particular it has significantly ramped up its annual revenue – in 2010, it reported sales of $6.5 billion; by 2020, that more than doubled, to $13.8 billion. Kingston reported $16.1 billion in revenue for 2022 and Pitchbook said the company had about $14 billion in sales last year.

Education: Technische Universität Darmstadt (Technical University of Darmstadt)

Investments: Tu in 2020 invested $50 million in Fluxergy, an Irvine-based diagnostics company launched in 2013 that had developed a test that in one hour identifies the virus that causes Covid-19.

Charitable Giving: The John and Mary Tu Foundation in 2023 donated $1 million to the Bowers Museum in Santa Ana.