What happened

Shares of solar microinverter maker Enphase Energy (ENPH 9.14%) popped 12.1% to close the trading day at $36.90 Tuesday. There appears to be only one announcement that sparked the rally.

This morning, Enphase said that it will announce its fiscal Q4 and full-year 2019 financial results two weeks from now, on Tuesday, Feb. 18, after close of trading at 4:30 p.m. EST.  

Solar inverters behind a row of solar panels in bright sunshine

Solar inverters behind solar panels. Image source: Getty Images.

So what

Yes, you read that right. Enphase only had to announce that it will announce something else to spark a rally in its stock. No further details were needed, or given.

This is kind of surprising when you consider that Enphase shares are already up more than 350% over the past year, and are trading within a few decimal places of 100 times trailing earnings. Nevertheless, absent any analyst upgrades, price target changes, or other news of note, this appears to be the announcement that added nearly $4 to the stock price.

Now what

Is that reasonable? It really depends on whether you believe Enphase will live up to expectations two Tuesdays from now. According to analysts who follow the stock, it is on course to earn $0.33 per diluted share in its fiscal fourth quarter (725% more than it earned in the year-ago quarter) on a 122% increase in sales to $205.3 million.  

If Enphase continues growing sales at a better than 100% clip, and earnings even faster than that, then a P/E ratio as high as 100 might be justified. Of course, one might quibble that it's better for investors to wait until the company confirms that it actually has grown that fast. Today, though, just the hint that Enphase might soon make this announcement was enough to send the stock flying.