That decline starts looking like the first move down off the major top.
Break under October 2020 lows confirms completion of the large (A)-(B)-(C) up rally off March 2020 lows.
That breakdown makes unlikely scenario where we can get one more push higher over January 2022 top. Most likely we made a multiyear top in January and we are watching now first moved of what will become a large correction of the whole rally since 2009 lows.
Despite the fact that currently we are under October low we still should consider it a strong level (4270 – 4340).
It is very possible that we will get a bounce back over that level in coming days.
The next strong level of support is around 4,190, 23.6% retracement of the rally started at the end of April 2020