Today’s digital giants are changing the definition of a diversified portfolio. As industrial giants like GE and Honeywell—once models of diversified portfolios—split up, consider how companies like Amazon, Apple, and Alphabet operate across many unrelated sectors, like e-commerce, cloud computing, entertainment, financial services, smart homes, logistics, and healthcare. As traditional diversification theories based on economies of scale and scope become less relevant in the digital age, the growth of AI is also ushering in new opportunities to create value with shared data, expertise, and network effects, and a new imperative for business leaders to reshape their strategies.