U.S. stocks tumbled toward the worst levels of last month’s selloff as global equities slid amid a rout in commodity and biotechnology shares.

The Standard & Poor’s 500 Index fell 2.6 percent to 1,881.85 at 4 p.m. in New York, down for a fifth consecutive session to a one-month low. The Russell 2000 Index slumped 2.9 percent to an 11-month low.

The S&P 500 is down 8.8 percent in the third quarter, poised for its worst fall since 2011. The benchmark is almost 12 percent below its all-time high set in May. The Chicago Board Options Exchange Volatility Index has closed above 20 for the past 26 sessions, the longest streak since January 2012.

A report today showed household spending climbed more than forecast in August and incomes also rose as the biggest part of the U.S. economy continued to power past a global slowdown. Separate data showed contract signings to purchase previously owned U.S. homes unexpectedly declined in August for just the second time this year, signaling residential real estate might have difficulty building on recent momentum.