S&P 500 Tumbles as Jobs Data Looms Over Fed Rate Decision

The S&P 500 index opened lower on August 31 at 7,672, continuing a streak of choppy and mostly downward sessions over the past two weeks.

Traders are adjusting their exposure ahead of this week's jobs data, which has taken on unusual significance as the Federal Reserve's September rate decision still hangs in the balance.

A strong jobs report would give the Fed cover to keep rates higher for longer, putting pressure on equity valuations. Conversely, a soft report could stabilize the index quickly.