Nasdaq feeds break hours after Jensen Huang vouches for CoreWeave, Carteret network disruption cuts data across all US equity markets

Nasdaq's equity data feeds broke around 11:15 a.m. New York time, hours into a rally built on the word of Nvidia chief executive Jensen Huang. A status message from the exchange blamed a network disruption at its Carteret data centre affecting multiple multicast groups, and warned customers to expect intermittent data gaps across all US equities markets — Nasdaq, Nasdaq Texas and Nasdaq PSX, hardware feeds and software feeds alike. Traders had spent the whole morning buying.

Huang's subject was CoreWeave, the cloud computing firm whose downsized IPO Nvidia helped rescue and in which it holds a stake of roughly $2 billion. The customer's strength is improving every day, he said; its cost of capital is "actually decreasing"; Nvidia does not need to backstop it. For several hours the market took his word for it.

Every part of the reassurance came from an interested party. Nvidia sells CoreWeave the machines that generate its revenue, rescued its downsized IPO and holds about $2 billion of its stock — and it was Nvidia's chief executive telling investors that the customer's borrowing costs are falling. The supplier, the rescuer and the shareholder are the same firm.

The tape broke at a moment when the arithmetic behind such promises is under strain. TSMC this week posted a sixth consecutive record quarter, and its shares fell on the news anyway. The profits are booked in Taiwan; the valuations sit on a handful of US names whose expected returns depend on data centres being financed, built and powered. American ten-year yields pushed through five percent in September, and every cash flow promised by an AI build-out is discounted at something close to that rate. A chief executive can announce that a customer's cost of capital is decreasing; the rate at which the market discounts the announcement is set elsewhere.

Nasdaq's status notice said customers "may experience intermittent data gaps". Within hours the market had rolled over.