AI Bubble Tracker · Listening for the pop.

Hyperscaler capital spending on data centres, servers and chips has climbed to a quarterly record, with the five biggest AI builders now devoting more than 100% of operating cash flow to capex in some periods, according to SEC EDGAR filings tracked by the AI Bubble Tracker. Sequoia partner David Cahn's estimate of the revenue the buildout needs continues to outrun the annualised revenue of OpenAI and Anthropic, while venture funding to AI startups keeps expanding its share of all startup investment. The tracker flags several warning signals: Nvidia customers are taking longer to pay and unsold stock is piling up, DRAM contract price increases are slowing sharply, and cloud backlogs have jumped largely on contracts from a handful of AI labs. It matters because capex now consumes all the cash these businesses generate before shareholders are paid, leaving borrowing and savings to fund the gap. Next, watch DRAM spot and contract prices for a sustained decline, Korea's monthly semiconductor exports, and whether server useful-life assumptions stretch further to prop up reported profit.