AI-driven market rally shows signs of overheating, economist warns

RSM chief economist Joe Brusuelas warns that the market is currently "frothy" and poised for a "healthy correction," despite S&P 500 and Nasdaq reaching new highs amid low volatility and strong AI enthusiasm. He highlights that RSM's composite equity index is one standard deviation above its long-term trend, a historical precursor to market corrections, indicating stretched valuations and concentration risk in the tech sector. Brusuelas also raises concerns about potential "malinvestment" in AI infrastructure, drawing parallels to the dot-com bubble, suggesting a shakeout is likely to remove speculators rather than a full bubble burst.

Analysis

Despite the S&P 500 and Nasdaq reaching new highs amidst low volatility, a cautionary outlook is emerging based on signs of market froth. RSM chief economist Joe Brusuelas highlights that RSM's proprietary composite equity index has moved one standard deviation above its long-term trend, a technical signal that has preceded market corrections in the last four business cycles. This suggests equity valuations are stretched, reflecting significant concentration risk in the technology sector and artificial intelligence specifically. While the broader economic backdrop remains supportive—with growth near potential, unemployment at 4.3%, and contained inflation—concerns are rising about potential 'malinvestment.' The proposed $100 billion investment by Nvidia into OpenAI's infrastructure is cited as an example of spending that could be excessive, drawing parallels to the over-investment in bandwidth during the dot-com bubble. The prevailing view is not that the market is in a bubble, but that conditions are primed for a 'healthy correction' that would likely remove short-term speculators.

Key Decisions for Investors

• Investors should review portfolios for concentration risk in the technology and AI sectors, as these areas are identified as having stretched valuations and are most vulnerable to a potential correction.
• Consider implementing hedging strategies or trimming positions in high-flying AI-related stocks to protect gains, given the historical precedent of a pullback when the RSM equity index reaches one standard deviation above its trend.
• Monitor large-scale capital expenditures, such as Nvidia's planned infrastructure investments, for signs of 'malinvestment', as unsustainable spending could impact long-term profitability and shareholder returns, echoing lessons from the dot-com era.
• While a short-term correction is possible, the supportive macroeconomic fundamentals suggest that long-term investors could view a significant market dip as a buying opportunity to enter positions once speculative excess has diminished.