Thiel Capital Warns AI Boom May Be Bubble
A Thiel Capital managing director says the AI boom could burst before the end of 2026, as infrastructure stocks and AI-linked debt show signs of stress.
Updated on Nov. 5, 2026 in Artificial Intelligence
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Jack Selby, managing director at Thiel Capital, warned at the SALT London conference that the AI boom may be a speculative bubble that bursts before the end of 2026. Shares of CoreWeave, Nebius, and IREN each fell more than 30% over roughly one month before the remarks.
Why it matters
Stress in the infrastructure companies building the AI economy's physical backbone preceded the warning, raising questions about financing for AI infrastructure. Skeptics also question whether sufficient revenue exists outside a small group of large players known as hyperscalers.
Shares of CoreWeave, Nebius, and IREN each dropped more than 30% over roughly a month, while some CoreWeave-tied debt traded at yields of around 15-16%, a rise that signals lenders see greater risk of not being repaid. It remains unclear whether these market moves will persist or whether the bubble warning will prove accurate.
The players
Jack Selby
Jack Selby is managing director at Thiel Capital, the investment firm whose leaders have publicly questioned the sustainability of the AI boom.
Thiel Capital
Thiel Capital is an investment firm associated with Peter Thiel, which has substantially reduced its exposure to Nvidia.
Elon Musk
Elon Musk is the chief executive of Tesla and SpaceX and has voiced concerns about AI-related debt in recent weeks.
The details
Selby made the remarks at the SALT London conference, and a projection in the source suggests financing may get harder for AI infrastructure players. Separately, Peter Thiel's hedge fund exited its Nvidia position, valued at around $100 million, and Thiel-linked firms have substantially reduced their exposure to Nvidia.
Timeline
2025 Q3: Peter Thiel's hedge fund exited its Nvidia position.
Roughly one month before November 5, 2026: CoreWeave, Nebius, and IREN shares fell more than 30%.
Late October to early November 2026: PIMCO's CEO, Elon Musk, and Apollo voiced concerns about AI-related debt.
November 5, 2026: Selby warned of an AI bubble at SALT London.
Before the end of 2026: Selby says the AI bubble could burst.
The Tech Race
The bubble warning follows a series of AI-related debt concerns raised by PIMCO's CEO, Elon Musk, and Apollo in late October and early November 2026. It places the AI infrastructure build-out in a broader contest over whether capital markets will keep financing the sector's expansion.
Higher borrowing costs for AI infrastructure companies could affect the pace of new data centers, cloud services, and AI products that consumers and businesses rely on. Shifts in financing conditions may also influence the prices and availability of AI tools people use day to day.
The takeaway
Watching debt yields and infrastructure stock prices can offer early signals about the health of the AI sector. Readers following AI investments may find these indicators more revealing than headline predictions alone.
Further reading
Follow the latest coverage in our Artificial Intelligence section for further context on the sector.
Source note: This article includes information reported by Crypto Briefing.
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