Last week was very bad for shares holders.
Let's take a look at 4-hour chart first at DJI30:

The 200 SMA was strong resistance, but finally the index managed to brake above it on September 15. There was another resistance - monthly pivot. Index failed 3 times this month to breake above this pivot. Finally, the fall begun. It stopped at monthly S1 and weekly S2 support.
And here is the same index, but on 1 hour chart:

The 200 SMA and weekly pivot which were very close to each other, failed as a support and a strong sell off has begun. We will see, if there will be any move up from this levels.