While the Dow is down just 50 points at the moment, both the S&P 500 and the Nasdaq are quietly down more than one percent. As shown in the first chart below, the Nasdaq just broke below its 50-day moving average for the first time since July, which means its multi-month uptrend is in big jeopardy. The S&P 500 is currently testing support at its 50-DMA, and the bulls are desperately hoping that it holds. The same thing happened for the S&P at the end of September, and the bulls prevailed. We'll see how it plays out this time around, but things definitely look a lot different now than they did just a couple weeks ago. The S&P's 50-day is right above 1,050, so that is the level to watch for the remainder of the day.