Today 04/22/21 the S&P 500 (SPX) came within eleven points of making a new all-time high before turning down sharply. Neither of the other two US main stock indices, Dow Jones Industrial Average or the Nasdaq Composite were able to make new all-time highs.
Today may have been the bulls last gasp to keep the bull market going.
The daily SPX chart courtesy of BigCharts.com illustrates momentum messages.

The SPX price low today was above the low recorded two days ago and closed today’s session almost unchanged from 04/20/21. Daily RSI was below its 04/20/21 reading – a bearish divergence.
MACD line have a bearish crossover and the Histogram has gone below the zero line.
Traders are short 50% non-leveraged SPX related funds from the SPX open on 04/12/21.
If the SPX moves below 4114.82, initiate an addition 50% short position in non-leveraged SPX related funds. For this 50% position use a move above SPX 4191.31 as a stop loss.