SPX daily Sept 29

The argument from bulls is that today's selling has been triggered by quarter end flows and window dressing but how confident can anyone be in that assessment? Or that there's a scope for a big bounce in Q4?

Certainly the price action in equities today doesn't fit with what's happening in bonds and FX so there's a reasonable basis for the belief but there's nothing like a 2.7% decline to the worst levels of the year to challenge a thesis.

In any case, the technical picture isn't pretty on the break below the June low. That level was 3636.87 and that will be the level to watch into the close.