The S&P 500 flies high fuelled by the Fed pivot optimism. The vertical rise above 3900 confirms the bullish MA cross on the daily chart, suggesting an acceleration to the upside. The index is testing the psychological level of 4000, which is also a former support from a mid-September sell-off. A breakout would put the September peak of 4150 within reach. The RSI shows an overextension and may prompt intraday buyers to take profit in the supply zone. The resistance-turn-support at 3900 would be the first level to monitor.