What happened 

Shares of residential solar installer Vivint Solar, Inc. (NYSE:VSLR) jumped 10.3% in October, according to data provided by S&P Global Market Intelligence, after the company got a little bit of good news about potential solar import tariffs.

So what 

In September, shares plunged because there was fear the Trump administration would put high tariffs on solar imports, causing shares to plunge. Last month was a reversal of course as fear of the worst tariffs began to subside. 

Row of homes, all with solar on their roofs.

Image source: Getty Images.

The International Trade Commission gave a preview of its tariff proposals, and the worst was a 35% tariff on cells and modules. But the others were lower, including one that proposed an import license fee that would then be used to support domestic manufacturing. No matter which one is chosen, the cost increase won't be so burdensome that Vivint Solar can't absorb it with a small price increase. 

Now what 

The final tariff ruling won't come down until early 2018 when President Trump will make a final decision. But the trajectory doesn't seem to be taking the negative path many had feared a few months ago. Conservative groups have joined liberal groups to voice opposition to tariffs; even Sean Hannity cut a radio ad against tariffs. That's good news for Vivint Solar -- and if the final ruling is in its favor, shares could rise even further.  

Travis Hoium has no position in any of the stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.