S&P 500 has formed an Evening Doji Star pattern (circled on the chart) which is a very reliable top and reversal pattern especially combined with other indicators supporting the reversal picture.
In this both RSI and MACD have been showing divergence for a couple of weeks (where instrument is making a new high but indicators are not)
That is a sign of weakness of the trend and an imbalance in the market.
Correction is in the cards where S&P 500 is likely to break below the upper very short-term rising trend line. A close below 4,455 is likely to lead to further selling to test the lower rising trendline.
A close below is likely to lead to further selling towards key support at around 4,328. Whether it will reach that levels is very uncertain.
A close below will demolish the medium-term bullish trend.
For S&P 500 to cancel the top and reversal scenario a close above 4,579 i.e., above the Dojo peak, is needed.
On weekly chart S&P 500 can perform a Shooting Star top and reversal candle if it closes today Friday around 4,508 i.e., approx. same level as the week open.