Quite often, the start of a quarter is a strong moment for stocks, presumably due to all of the pension and 401k money that flows in as a function of the calendar date.
This one seems to be starting out very weak, which seems just a bit more ominous. With all the recent weakness, you might think we’d be due for a bounce here.
Not so much.

Still, US futures are much stronger than Europe at the moment:

Part of the explanation for this weakness is that investors are supposed to be fretting over growth prospects.
Growth gloom grows at start of third quarter
Thursday 12:00 BST. Bulls have started the third quarter as they finished the second: with a trip to the slaughterhouse.
European bourses opened with heavy losses after Asian stocks absorbed Wall Street’s late slide and following confirmation that the pace of manufacturing growth in China is slowing.
The FTSE All-World equity index is down 0.4 per cent and commodities prices are lower as investors, worried about the prospects for global economic growth, continue to take risk off the table. “Haven” government bond yields are stuck near multi-month lows.
It is noticeable, however, that the euro is higher, suggesting previous “risk-off” correlations are not being slavishly adopted by traders, and this may have helped stocks pare initial losses. S&P 500 futures, which were down 0.5 per cent, are now flat.