The S&P 500 has remained relatively resilient even as market participation has weakened, creating a widening gap between the index and the average stock. Morgan Stanley strategist Michael Wilson said fewer companies have been driving gains, while more than half of Russell 3000 stocks had fallen at least 20% from their June highs by late September.
The deterioration accelerated after the Federal Reserve’s Jackson Hole meeting, as investors began pricing a more hawkish path. The share of S&P 500 companies trading above their 200-day moving average fell from roughly 75% to below 50%, while the index held up considerably better.
Wilson said the divergence would eventually have to close in one of two ways: breadth could recover to match the index, or the index could fall toward the weaker breadth reading. If bond-market volatility remains elevated, he expects the S&P 500 could decline about 5% to 10% before the correction beneath the surface is resolved.
He described such an index-level decline as potentially constructive, arguing that a final correction could create an opportunity to add riskier stocks. Morgan Stanley continues to favor large-cap quality companies, particularly asset-light and services-oriented businesses with stable margins, free cash flow and rising earnings estimates.
The firm’s market view remains tied to a mid-cycle pattern in which earnings growth offsets lower valuations and leadership shifts away from high-beta groups. Autos, semiconductors and short-cycle industrial companies have weakened after earlier gains, while the median stock’s earnings growth remains in the mid-teens and the S&P 500’s forward valuation has moved near 19 times.
Another factor in the outlook is artificial intelligence. Morgan Stanley said companies adopting AI are showing stronger margins and earnings trends, while current consensus forecasts assume some of those benefits fade in later years. That view supports a selective approach combining durable AI-related businesses with companies whose improving fundamentals may not yet be fully reflected in their valuations.
Independent market analysis has also highlighted the unusual gap between the index and its constituents, though it cautioned that weak breadth alone has limited evidence as a predictor of crashes. The immediate signals Morgan Stanley is watching are bond volatility, funding stress and whether turbulence spreads from fixed income into equities. If those pressures ease, breadth could improve; if they persist, the index may face further pressure.