Forbes 400: Under-40 Billionaires Jump to 10, Anthropic Founders Take 4 Spots on AI Wealth Boom

Forbes' 2026 Forbes 400 list shows the number of billionaires under 40 rose to 10 from four a year earlier, with seven self-made thirtysomethings whose fortunes stem from the artificial intelligence boom. AI startup Anthropic accounts for four of the new entrants. Anthropic co-founders Tom Brown, 39; Daniela Amodei, 39; Jack Clark, 37; and Sam McCandlish, 36, each hold estimated net worth of $15.5 billion, tied at No. 75. The Forbes 400 entry threshold hit a record $4.4 billion. Founded in 2021 by seven former OpenAI employees, Anthropic reached a $965 billion valuation after a $65 billion funding round in May. The founders have pledged to donate 80% of their wealth. OpenAI co-founder and President Brockman, 38, also joined the list. Competition is intensifying after OpenAI's GPT-6 Astra launch this month. Reuters reported Anthropic may delay its IPO until after the U.S. midterm elections in November. Anthropic's annualized revenue exceeded $65 billion as of July, above OpenAI's $40 billion.