The world's ultra-rich experienced a significant wealth increase in 2025, with 17 out of 18 billionaires tracked whose fortunes exceed $100 billion seeing gains. This surge was driven by a strong global equity market, particularly investments in artificial intelligence, favorable economic indicators, and expected lower interest rates. Notable gainers included Alphabet co-founders Sergey Brin and Larry Page, and Elon Musk, whose net worth crossed $600 billion. Bill Gates was the sole exception, with his net worth declining due to philanthropic commitments.