The S&P 500 climbed above 6,900 for the first time on October 28, 2025, but nearly 80% of its stocks fell that day. This made it the weakest market breadth ever recorded for a positive session. This anomaly illustrates the rally’s extreme concentration and raises concerns about market fragility, even as prediction markets show optimism for further gains. A Rally Driven by a Few Stocks As of this writing, the S&P 500 (SPX) traded at 6,890, a modest correction after topping out at 6,911 on Tuesday
source: https://beincrypto.com/sp500-weak-breadth-crypto-shift/