US stock indices test support levels amid selloff

US stock indices declined again today, following the sharp losses from the previous session. Treasury yields surged as market participants raised their expectations for additional Federal Reserve interest rate hikes. Higher yields put pressure on equities by increasing borrowing costs and diminishing the current value of future profits. This effect is particularly acute for growth stocks.

Each major index is now probing a different downside level. These levels serve as short-term indicators: if support holds, buyers may find room to push higher; a decisive break with momentum would give sellers firmer control. A quick dip below a level is one thing, but sustaining the break adds conviction to the move.

A summary of the key levels is provided below:

• S&P 500: The index trades between its 100-hour moving average at 7667.44 and its 200-hour moving average at 7682.65, a narrow band. A drop below the 100-hour moving average with follow-through momentum would tilt the short-term bias further toward sellers. The next downside target is the swing area between 7573 and 7617. On the upside, reclaiming the 200-hour moving average would indicate a potential return of buyer control.

• Nasdaq Composite: The index tests the underside of a broken trendline and a swing zone from 26,676 to 26,856. Today's low of 26,706 fell within that zone. Swing zones matter because prices have reversed there before; when revisited, they can attract both buying and selling pressure. A break below 26,676 would shift focus to the 100-hour moving average at 26,477, then the 200-hour moving average at 26,393. A move above 26,856 would strengthen the buyers' position. The failed breakout is significant: the index hit a new all-time high earlier this week but could not sustain it.

• Nasdaq 100: The selloff has pulled the index back toward 30,195, a level based on swing highs from August. Today's low reached 30,204, just above that support. Buyers have held so far, but a break below would open the path to 29,947. The 100-hour moving average sits lower at 29,594.33. If support continues to hold, sellers who positioned for a breakdown may have to cover, fueling a rebound. Like the Composite, the Nasdaq 100 closed at a record high earlier this week before reversing lower.

The question now is whether buyers can defend these levels after yesterday's yield-driven decline. Observing how price behaves at support and whether any break holds will provide more insight than the initial move through a level alone.