LeCun Warns of AI Bubble, Citing xAI Failure; Chip Stocks Face Overvaluation Concerns

"AI Godfather" Yann LeCun warned on June 18, 2026, that Elon Musk's xAI has "in some ways already failed," predicting a catastrophic "AI bubble explosion" for the entire industry. LeCun cited xAI's core team exodus and difficulty attracting top talent. He also highlighted that most AI labs rely on investor subsidies, unsustainable without significant cost reduction or price increases. This warning aligns with Wall Street's growing concerns about overvalued chip stocks. The VanEck Semiconductor ETF (SMH) has seen its components, including NVIDIA (NVDA), Advanced Micro Devices (AMD), Broadcom (AVGO), and Taiwan Semiconductor Manufacturing Co. (TSM), nearly double in the past six months, with its forward P/E ratio surging above 31x, a one-year high. Morgan Stanley data shows nearly 80% of S&P 500 semiconductor companies have seen annual profit estimates upgraded, a level last seen in 2003, historically preceding estimate downgrades. Market volatility has intensified, with the SMH ETF experiencing daily declines exceeding 1% since early June. The spread between the Nasdaq volatility index and the broader market volatility index is at its widest since late 2020. Analysts advise investors to "hold but not add" to current positions, suggesting a pivot to lower-risk, non-AI beneficiaries amidst potential industry rebalancing.