Wall Street analysts have sharply raised their profit growth forecasts for S&P 500 companies, sparking concerns that an “earnings bubble” may be forming ahead of the upcoming second-quarter earnings season. According to recent data, earnings expectations for the coming year have climbed to an anticipated 25 percent increase, driven primarily by a resilient U.S. economy and robust demand linked to artificial intelligence (AI) technologies.

This surge in projections is the fastest since the post-pandemic recovery phase, with consensus estimates rising nearly 20 percent over the past six months—the largest jump since 2021. While some market participants see this as a sign of strength, others warn that these optimistic forecasts may prove unsustainable. Rising costs among AI-focused companies, potential softening in demand, or difficulties in converting increased spending on AI into profits could cause actual earnings to fall short of expectations.

Ben Inker, co-head of asset allocation at GMO, described the sharp rise in forecasts as “exceedingly high,” noting that such rapid growth in earnings projections is typically observed only during crisis recoveries. He added that the market may soon confront the reality that these estimates will not materialize.

Much of the elevated earnings optimism centers on chip manufacturers and so-called hyperscalers, who are benefiting from soaring demand for computing power driven by AI advancements. However, analysts at Capital Economics cautioned that earnings and capital expenditure assumptions in AI-related equities may be difficult to sustain, raising the risk of a broader market downturn if these expectations are revised downward.

Michel Lerner, head of UBS’s investment analytics platform HOLT, echoed similar concerns, warning of an “earnings bubble” within the AI sector. While current profit levels are exceptional and likely to continue in the near term, he expressed skepticism about the ability to maintain such profitability and growth over a longer horizon.

The strong earnings forecasts have helped push U.S. stock indices to record highs. The S&P 500 has climbed nearly 20 percent in the past year, and the Nasdaq Composite has risen about 25 percent, including its best quarterly performance in six years in the second quarter. Nonetheless, analysts emphasize that valuations remain relatively moderate, with the S&P 500 trading at about 20 times forward earnings—lower than levels seen last year, during the 2020 post-pandemic rebound, and well below the dotcom bubble peak.

Some experts caution that low price-to-earnings multiples might reflect stocks approaching their peak earnings, potentially signaling caution for investors. Sarah Ketterer, CEO of Causeway Capital Management, suggested that such conditions “may not be a good time to invest.” Conversely, Charles-Henry Monchau, chief investment officer at Swiss bank Syz, expressed less concern about an index-wide bubble but highlighted concentrated risks within the AI investment complex. He advised diversification beyond AI-related sectors to mitigate potential volatility tied to this segment.

Additional market vulnerabilities include elevated levels of equity and debt issuance, exemplified by recent large-scale offerings such as SpaceX’s initial public offering and significant debt transactions. Furthermore, expectations for higher U.S. interest rates have shifted, with traders now pricing in at least one rate hike by year-end, contrasting with earlier bets on multiple cuts. These factors may tighten profit margins and increase pressure on corporate earnings.

Kasper Elmgreen, chief investment officer for fixed income and equities at Nordea Asset Management, noted a “very narrow margin of safety” on current earnings levels. He emphasized that the critical question for markets is the duration for which positive earnings surprises can continue amid heightened expectations and emerging signs of strain.