Mako Surgical Corp. (Nasdaq: MAKO) shares gained 11.4% to $23.89. Volume was 1.1 million shares, or nearly twice its daily average after the company said late Wednesday that it had an order for 11 surgery systems from Health Management Associations Inc. (NYSE: HMA)

Intel Corporation (Nasdaq: INTC) was a volume leader in early Thursday afternoon trading, dealing in 46.9 million shares, erasing the gap with its daily average of 59.2 million. Prices were 2.1% lower to $20.03, amid general weakness in the tech sector.

Horizon Lines Inc. (NYSE: HRZ) plummeted 25.9% in price to 94 cents, on volume of 5.4 million shares, nearly nine times its daily average, as the company contemplates bankruptcy.