The broader US stock indices are lower again today after yesterday’s sharp decline. Treasury yields spiked as traders increased their expectations for further Fed rate hikes. Higher yields can weigh on stocks because they raise borrowing costs and make future earnings less valuable in today’s terms. That pressure can be especially pronounced for growth stocks.Each index is now testing a different downside level. These levels are short-term barometers for traders: holding support could give buyers room to push back, while a break with momentum would put sellers more firmly in control. A brief move below a level is one thing; staying below it adds conviction to the break.In the video above, I walk through the levels and explain why they matter. Here is the quick summary:S&P 500: The index is trading between its 100-hour moving average at 7667.44 and its 200-hour moving average at 7682.65. That leaves traders with a narrow area to watch. A move below the 100-hour moving average, followed by momentum away from it, would tilt the short-term bias further toward the sellers. The next downside target would be the swing area between 7573 and 7617. On the upside, reclaiming the 200-hour moving average would be a step toward giving buyers more control.Nasdaq Composite: The index is testing the underside of a broken trendline and a swing area between 26,676 and 26,856. Today’s low of 26,706 fell inside that area. Swing areas matter because prices have previously turned there; when revisited, they can again draw both buyers and sellers. A break below 26,676 would shift attention to the 100-hour moving average at 26,477, followed by the 200-hour moving average at 26,393. Conversely, a move above 26,856 would improve the buyers’ position. The failed breakout is part of the story: the index reached a new all-time high earlier this week but could not sustain the move.Nasdaq 100: The decline has brought the index back toward 30,195, a level marked by swing highs from August. Today’s low reached 30,204, just above that support. Buyers have held it so far, but a break below would open the door toward 29,947. The 100-hour moving average sits further down at 29,594.33. If support continues to hold, sellers who positioned for a breakdown may have to buy back their positions, adding fuel to a rebound. Like the Composite, the Nasdaq 100 closed at a record level earlier this week before reversing lower.The question now is whether buyers can defend these levels after yesterday’s yield-driven decline. Watch how price behaves at support and whether any break holds. That will tell traders more than the first move through a level alone. This article was written by Greg Michalowski at investinglive.com.