The S&P 500 Index ($SPX) and SPDR S&P 500 ETF Trust ($SPY) are experiencing significant volatility as they test key support levels. The $SPX is nearing the 5450-5500 zone, with major support at 5506 and potential targets at 5465 and 5455 if it breaks lower. The $SPY is also under pressure, needing to defend the 549 level or its 50-day moving average (DMA). Traders are closely watching the market's reaction to the upcoming Nonfarm Payrolls (NFP) report, which could trigger further market movements. The $SPX has held the 5506 support for two days, but a break below this level could lead to a selloff towards the 5440s. Additionally, the $SPX is nearing the 21/55 MA and 38.2% retrace support levels, and a reclaim of the prior range would be a bullish development.