Shares of body-camera maker Axon Enterprise Inc. (NASDAQ: AAXN) jumped as much as 28.1% in trading Wednesday, after the company reported fourth-quarter 2017 earnings that beat expectations. As of 1:35 p.m. EST shares were holding gains, trading 28% higher on the day.Fourth-quarter revenue jumped 15.3% to $94.7 million and the company swung to a net loss of $2.1 million, or $0.04 per share, from a $6.3 million a year ago.