Top trader Najarian buys chip stock

CNBC "Halftime Report" trader Jon Najarian purchased shares of Ambarella on Wednesday for his model portfolio. In other moves, he also sold Transocean and half of his Community Health Systems position.

Ambarella is a key image processing supplier for GoPro. The company's chips are used in security, wearable, auto and drone camera products.

Watch the video below to find out why Najarian made the moves.