The S&P 500 was down 0.6% in midday trading to 2,711.92.
The Dow Jones Industrial Average fell 1% to 24,633.27.
The Nasdaq declined 0.2% to 7,359.41.
The yield on a 10-year Treasury bond dropped 0.4% to 2.87%.
The price of gold was 0.6% lower to $1,327.
Spectrum Pharmaceuticals Inc. (Nasdaq: SPPI) in Irvine was down 15% to $17.85 and a $1.8 billion market cap. The cancer and blood disease drug maker missed expectations on revenue and reported a larger net loss, year-over-year, in quarterly results yesterday.
Emerald Expositions Events Inc. (NYSE: EEX) in San Juan Capistrano was down 4% to $21.34 and a $1.6 billion market cap. The trade show producer said a secondary offering of 7 million shares by affiliates of majority owner Onex Partners Manager LP at a maximum price of $21.27 apiece, had begun; underwriters get a 1.05 million-share over-allotment. Emerald raised $264 million in an April IPO priced at $17 a share.