Company: First Solar, Inc.

(Reuters) - The United States hit Chinese solar companies with punitive import tariffs of 30 percent or more on Thursday, ruling they had dumped cut-price solar panels into the U.S. market.

A look at the 10 biggest percentage gainers on Nasdaq at the close of trading:

Shares of Chinese solar-panel makers fell Thursday after the U.S. Commerce Department moved to impose high tariffs on their products.

Shares of First Solar Inc. plummeted Wednesday after investment firm Greenlight Capital Inc. disclosed that it no longer held "put" options on about 113,000 shares of the solar panel manufacturer.

The first commercial solar array approved and built on federal public land began producing electricity Monday from a sun-baked site in the Mojave Desert south of Las Vegas near the Nevada-California state line.

Though it posted a surprise quarterly loss on Thursday, First Solar has raised its profit outlook.

First Solar posted a surprise quarterly loss on Thursday, but raised its full-year profit outlook as it drives down production costs for its solar panels, while peer SunPower slightly beat Wall Street forecasts.

A shakeout that is rattling the solar panel industry has sent First Solar, once among the industry's biggest and strongest companies, to a wide quarterly loss.

Stocks ended near session highs Tuesday, with all three major averages logging their best rally in a month, helped by a handful of positive earnings reports and as fears over Europe diminished.

First Solar said it would cut production of its thin-film solar panels and slash 2,000 jobs, or about 30 percent of its workforce, as the largest U.S. solar maker speeds up its cost-cutting efforts.

U.S. stock index futures were higher Tuesday following a handful of better-than-expected earnings reports and as investors seemed to overlook a handful of disappointing economic news.

A glut in solar panels has driven down prices, and the oversupply may take a while to clear, according to industry executives. At the same time, low-cost natural gas is making gas-fired plants more attractive. the New York Times reports.

Suntech Power Holdings’ chief executive said the Chinese solar company expects to return to profit, along with the entire industry, as prices stabilize.

First Solar is in active discussions with several potential additions to its board of directors, people familiar with the matter said.

Clean tech has become a major destination for investors, from venture capital firms to ordinary shareholders. Click ahead to see 10 select, large ETFs with a strong focus on clean-tech holdings.