What: Shares of action camera manufacturer GoPro (NASDAQ:GPRO) shot up 22.47% in April, according to S&P Capital IQ data, as investors reacted positively to the company's first-quarter earnings, bullish second-quarter guidance, and analyst upgrades.

GPRO Chart

GPRO data by YCharts

So what: GoPro's growth story continues. On April 28, the company posted a year-over-year revenue increase of 54% by growing its top line to $363 million in Q1. On an adjusted EPS basis, the company reported $0.24. In both totals, the company performed better than expectations of $341 million and $0.18, respectively.

In a sign that the company is owning the action-capture market, the company reported research firm NPD's data that the top five products on a units sold basis in the combined digital camera and camcorder category are GoPro models.

Furthermore, the company guided to higher figures than analyst consensus. The company expects second-quarter revenue to be in the range of $380 million-$400 million, a midpoint nearly 17% higher than analysts' estimates of $333.7 million. On an earnings per share basis, the company expects second-quarter EPS in the range of $0.24-$0.26, 56% higher than the $0.16 analysts were predicting at the midpoint.

Now what: GoPro's been a volatile stock, and this should continue. The company is a high-growth company and estimates about the company's future growth will vitally matter to investors. For example, after the company's fourth-quarter earnings report, the stock violently reversed after the company reported solid earnings but investors reacted poorly to first-quarter EPS guidance of $0.15-$0.17 per share and a departing executive. As we witnessed from the $0.24 the company reported, the company's estimate was conservative.

Following the most recent report, analysts at Raymond James upgraded the company from market perform (essentially neutral) to outperform with a note that "[we] expect EPS growth of 25% to persist through 2016." If GoPro continues to execute, it is entirely possible that Raymond James is underestimating GoPro's bottom-line growth.