The S&P 500 closed at a record high Friday as a surge in technology shares capped the sixth straight week of gains for U.S. equities, even as warnings about the rally's sustainability intensified.
"The momentum factor in the short-term feels very fragile," said Michael Romano, head of hedge fund equity derivatives sales at UBS, who noted that some AI-linked stocks had rallied more than 50 percent from their March lows.
The Philadelphia Semiconductor Index soared 11 percent over the five trading days, with AMD's weekly Relative Strength Index (RSI) nearing its highest overbought levels on record. The rally showed signs of fragility Thursday when the iShares USA Momentum Factor ETF (MTUM) fell 1.8 percent, its worst day since March, before recovering losses Friday. Market breadth continued to deteriorate, with value and low-volatility factors underperforming.
The extreme concentration in a handful of winners creates a high risk of a sharp market correction or a violent rotation into defensive assets, with strategists pointing to the potential for a pullback if the few leading stocks falter. The U.S. 10-year Treasury yield held steady, while WTI crude oil saw a weekly decline.
Wall Street Sounds the Alarm
The chase for winners has pushed market indicators to levels that have historically preceded pullbacks. Barclays global equity strategist Alexander Altmann warned this week that the current momentum rally has reached "extreme" levels. Data from Goldman Sachs' trading desk showed that high-momentum stocks have stretched valuations and that institutional positioning is at a multi-year high.
This mechanical chase higher—where rising prices and falling volatility force investors to buy more—has spread to other asset classes, including junk bonds and cryptocurrencies. However, the rally's foundation appears unstable. While the semiconductor sector's forward price-to-earnings ratio of 24.4 remains below its 2024 peak, its price-to-sales ratio is at an all-time high, signaling significant valuation risk.
The narrowness of the advance is a primary concern. The quality factor, which favors companies with strong profitability and low leverage, has seen its correlation with the momentum factor fall to the lowest in nearly a year. This divergence is a classic feature of speculative, risk-on rallies where defensive strategies are left behind, increasing the market's vulnerability to sharp reversals.
This article is for informational purposes only and does not constitute investment advice.
