China's market selloff sent domestic markets tumbling to a sharply lower close with the Dow skidding 127 points to 17,440. Nasdaq plunged 48 points to 5,039.

On the upside

Magnetek (Nasdaq: MAG) will be acquired by Columbus McKinnon for a premium of approximately $188.9 million.

Beacon Roofing Supply (Nasdaq: BECN) will pay approximately $1.1 billion to acquire Roofing Supply Group.

Cryoport (Nasdaq: CYRX) expanded its portfolio of programs to include 45 clinical trials.

On the downside

A. M. Castle & Co. (NYSE: CAS) will be replaced on the S&P SmallCap 600 after market close on Friday, July 31.

First Majestic Silver (NYSE: AG) will acquire SilverCrest Mines.

Freeport-McMoRan (NYSE: FCX) reached an agreement with the Indonesian government for a six month export extension but the stock price fell.

In the broad market, declining issues outpaced advancers by a margin of more than 5 to 2 on the NYSE and by nearly 5 to 2 on Nasdaq. The broader S&P 500 dropped 12 points to 2067. Bitcoin added$2 to $291.