Gainers:

Aytu Bioscience Inc (NASDAQ:AYTU) shares are up 9 percent. No news was immediately available.

Smart Global Holdings Inc (NASDAQ:SGH) shares are up 7 percent after reporting a fourth-quarter earnings beat. Adjusted earnings came in at $1.72, beating estimates by 6 cents. Sales came in at $374 million, beating estimates by $5 million. The company issued strong first-quarter earnings guidance.

Losers:

Vaxart Inc (NASDAQ:VXRT) shares are down 9 percent after gaining 89 percent in the regular trading session. The company earlier announced that it will present new data from a Phase 2 study that showed its oral tablet vaccine provided a 39-percent reduction in flu illness.

Collectar Biosciences Inc (NASDAQ:CLRB) shares are down 5 percent. No news was immediately available.

New Age Beverages Corp (NASDAQ:NBEV) shares are down 1 percent on chatter that the company is in talks with retailers for CBD pre-orders.