The S&P 500 is starting the trading day just barely above its 50-day moving average, but the percentage of stocks in the index trading above their 50-DMAs is only at 43%. Also, as shown in the second chart below, there are now more stocks oversold (22.6%) than overbought (21%). Both of these readings on breadth are a sign of weakening internals. This is a key trend to keep an eye on.