Legendary chart analyst Louise Yamada: ... "The bigger the base, the higher in space..."
We have had this sideways movement since June, but let's focus down on this nearly mechanical up-and-down motion between 2,820s and 2,930 starting at the end of July. This is clearly a significant pattern. Even if you DON'T believe in technical analysis and a chart is just squiggles to you, most market participants believe in this voodoo and will act accordingly.
Let's focus on the sideways movement from the end of July 'til today. We have an extremely well-defined resistance level