It has been nearly a year since Openai released gpt-4, its most sophisticated artificial-intelligence model and the brain-of-sorts behind Chatgpt, its groundbreaking robot conversationalist. In that time the market capitalisation of America’s technology industry, broadly defined, has risen by half, creating $6trn in shareholder value. For some tech firms, growing revenue is starting to match sky-high share prices. On February 21st Nvidia, which designs chips used to train and run models like gpt-4, reported bumper fourth-quarter results, sending its market value towards $2trn. ai mania has also lifted the share prices of other tech giants, including Alphabet (Google’s corporate parent), Amazon and Microsoft, which are spending big on developing the technology.
