On 08/16/21 the S&P 500 (SPX) peaked at 4480.26 which was almost a bullseye hit of the Fibonacci resistance target illustrated in the 07/27/21 blog “Market Nexus Points”.
The weekly SPX chart courtesy of Trading View updates the chart illustrated in that blog.

Logarithmic scale is usually the best method to measure Fibonacci points after large percentage moves. However sometimes Fibonacci coordinates can be discovered using Arithmetic scale which yields a target of 4509.83. If the current peak at SPX 4480.26 does not hold the SPX could be drawn to 4509.83.
The “Market Nexus Point” blog noted that the Fibonacci time forecast targeted the first week of August 2021 as a bullseye time target. The leeway for that target is plus or minus one to three weeks. The SPX high at 4480.26 came within the time leeway.
The daily SPX chart focuses on near-term support and resistance.

Assuming the high at 4480.26 is not exceeded a break of the double bottom 4372 to 4373 could open the door for a significant drop – possibly 10% or lower from the all-time high. Note the daily RSI + MA and Stochastic both have bearish crossovers. So far daily MACD does not have a bearish crossover.
A move above 4480.26 opens the door to the 4484 – 4509 zone.
The SPX – 5 – minute chart zooms in on the intraday action.

So far, the decline from the all-time high has been a corrective three-wave pattern and implies a move back to at least the 4480.26 high. If within the next one or two trading days the SPX fails to break above the all-time high, then a move below the 08/17/21 low could open the door for an attack of the double bottom at 4372 – 4373.