SunPower Corporation (NASDAQ:SPWR) and First Solar, Inc. (NASDAQ:FSLR) both rallied this week after the U.S. slapped another tariff on Chinese solar panels. However, both companies gave back those gains today as investors began to consider the negative impacts of those tariffs on them.

Sunpower Corporation

Positive impacts for SunPower, First Solar

According to MarketWatch, officials set preliminary duties of between 18.56% and 35.21% on Tuesday. Most companies would see a 26.89% tariff placed on their products. Investors initially saw the U.S. Dept. of Commerce’s decision as a positive for both SunPower Corporation (NASDAQ:SPWR) and First Solar, Inc. (NASDAQ:FSLR) because it gives them a pricing edge over Chinese solar panel makers.

Shares of both companies edged upward Wednesday. SolarCity Corp (NASDAQ:SCTY) also gained on Wednesday, climbing as much as 4% from positive expectations about the tariff. However, the stock joined SunPower Corporation (NASDAQ:SPWR) and First Solar, Inc. (NASDAQ:FSLR) today in declining by nearly 2%.

Meanwhile shares of Chinese solar panel makers Trina Solar Limited (ADR) (NYSE:TSL) and Yingli Green Energy Hold. Co. Ltd. (ADR) (NYSE:YGE) slumped on Wednesday in the wake of the news. Those stocks had not recovered their losses as of this writing. JA Solar Holdings Co., Ltd. (ADR) (NASDAQ:JSO) didn’t see a negative effect on its shares until a day later.

Negative impacts for U.S. solar companies

Today, however, investors began to realize that Chinese solar companies might not be the only ones negatively impacted by the tariff decision. Citi analysts say it could hamper growth of the U.S. solar industry as a whole, thus impacting all solar companies—even those based in the U.S. They believe that some companies might have to abandon some projects “if they can’t squeeze suppliers” or otherwise pass their higher costs on to their customers, thus raising their prices. The Citi team said that no matter what happen, at least one of the stakeholders in the solar value chain will see a negative impact from the tariff.