Generally speaking, the stock index futures markets stumble into October
The last week (or so) of September is notoriously weak for equities, and strong for Treasuries. We don't see any reason to buck the seasonal trend. After all, Friday's bloodbath on Wall Street is a sure fire sign that investors have not gotten over the mid-August stock market "crash".
Although the Fed meeting is behind us, we still have to worry about the details of Janet Yellen's speech on Thursday at the University of Massachusetts-Amherst. Oddly enough, the financial markets sometimes react to non-FOMC speeches than they do the official Fed meetings. Be prepared for volatility.