Colfax Corp. shares plummeted 14 percent in early trading on the news that the technology conglomerate plans to purchase private equity-owned orthopedics company DJO Global Inc. (for DonJoy Orthopedics) for $3.15 billion in cash. The Annapolis Junction, Md.-based company sees DJO as the basis of a medical technology platform business; it's also evaluating strategic options for disposing of its existing air and gas handling business.