Chip stocks slide after report OpenAI revenue is ~$20bn below prior estimates

The Financial Times reported that OpenAI told investors its annualized revenue was approaching $50 billion at the end of September 2026, about $20 billion below the roughly $70 billion figure several outlets had reported late last month. The PHLX Semiconductor Index fell 3.39% to 12,623.72 on October 8, 2026, according to Invested Alpha, which cited Reuters for the 3.4% decline in chipmakers. The group had gained more than 80% this year going into the session, per Invested Alpha, leaving room for a pullback once the news landed.

The difference between the two figures comes down to how revenue is counted. Anthropic includes sales made through cloud partners such as Amazon Web Services and Google Cloud in its annualized figure, while OpenAI does not, according to Investing.com, citing the FT. The roughly $70 billion number came from investors' attempts to put the two companies on a like-for-like basis. OpenAI has told investors that its revenue grew more than 70% over the period, so the company did not miss anything it had promised. What changed was the market's working estimate of one of the most closely watched numbers in the AI economy.

The losses were concentrated in companies whose sales depend most directly on AI build-outs. Coherent fell 9.63% to $302.35, Lumentum lost 5.62% to $1,048.60, Micron dropped 4.79% to $1,035.84, Broadcom fell 4.35% to $360.14, AMD lost 3.9% to $620.68, and Nvidia fell 2.94% to $230.48, all per Invested Alpha. Coherent had been down about 5% at midday, according to CNBC, so the selling deepened through the afternoon. Samsung Electronics' record quarterly profit forecast earlier in the day did not lift memory stocks, per Invested Alpha.

Broadcom had its own headline. The Wall Street Journal reported that the company is working to arrange more than $50 billion in financing tied to the custom AI chips it is developing with OpenAI, and has held talks with private credit firms including Apollo and Blackstone. The discussions are at an early stage and the size could change. Broadcom and OpenAI have said they plan to deploy 10 gigawatts of custom accelerators, starting in the second half of 2026 and running through 2029. Reuters noted another worry in the background: the AI build-out has leaned heavily on debt, and rising interest rates could become a headwind. A day after the Fed's September minutes showed most officials expecting another hike by year-end, Fed Governor Christopher Waller said Thursday he anticipates additional increases if the data come in as expected.

The selling was not limited to chips. CNBC reported that Applied Digital fell nearly 2% at midday even after reporting fiscal first-quarter revenue of nearly $342 million, up 322% from a year earlier, and that data-center power supplier Bloom Energy was down nearly 5% at that point. One chipmaker moved the other way. GlobalFoundries rose 2.68% to $49.36 after announcing a five-year, $2 billion agreement to manufacture silicon interposers for TSMC. The parts will be made at GlobalFoundries' fab in Malta, New York, which the company plans to expand. Once running, it would be the first US-based source of interposers for TSMC's CoWoS packaging technology, with production expected to begin in the first half of 2028. The stock had been up as much as 7% earlier in the session before giving back part of the gain in the broader selloff.

The macro backdrop added pressure. The US 10-year Treasury yield has remained around 5.3%, close to its highest levels since 2002, while the 30-year yield has approached 5.7%, per Wealth DFM. The Fed raised interest rates by 25 basis points at its September meeting, taking the target range to 3.75-4.00%. Brent surged above $105 on Thursday before retreating towards $103 as hopes of diplomatic progress resurfaced. Wealth DFM noted that reports questioning the scale of OpenAI's annualized revenues contributed to renewed scrutiny of AI-related valuations, with chipmakers among the weakest performers. The underlying issue is increasingly one of returns on investment: investors want evidence that the extraordinary amounts of capital being committed to data centres, chips and infrastructure can generate sufficient revenue and cash flow to justify that spending.

Thursday's move was a reaction to a reported figure, not to a change in any company's guidance. The next real test comes when chipmakers and cloud providers report quarterly results and update their spending plans. Third-quarter earnings season begins on Tuesday with several major US banks scheduled to report, per Wealth DFM. Thursday also brings earnings from Taiwan Semiconductor Manufacturing Company, providing an early indication of demand across the semiconductor and AI supply chain. Wednesday's US inflation report will help determine how much flexibility the Federal Reserve has to respond. August headline inflation stood at 3.4% year-on-year, while core CPI was 2.4%. The September figures will provide an important indication of whether higher energy costs are beginning to spread into other parts of the economy. Until then, the gap between a $50 billion and a $70 billion run rate is likely to stay part of how investors read every AI-related headline.