What: Shares of solar inverter and optimizer company SolarEdge Technologies Inc (SEDG -2.16%) jumped as much as 28% today after it reported fiscal-first-quarter results.

So what: Revenue jumped 72% to $115.1 million, improving 16.9% sequentially as well. Net income jumped 55% to $14.4 million, or $0.32 per share, and on an adjusted basis was $0.36 per share, beating estimates of $0.30.  

Management also said that fiscal-second-quarter revenues would grow slightly to $118.0 million-$121.0 million and gross margin will be between 28% and 30%.

Now what: SolarEdge is riding the growth in residential solar in the U.S. by expanding partnerships with the industry's biggest companies: Vivint Solar and SolarCity. It's growing demand from those two companies that's driving growth over the past year.

While SolarEdge's forward P/E of 10 looks attractive today, 2017 could be a year of shrinking revenue if the Investment Tax Credit, or ITC, isn't extended, so there are clouds on the horizon. That kind of uncertainty and the fact that competitors are starting to launch products in the company's space is enough to make me stay away from the pop in the stock today.