Shares of Nike Inc. fell by close to four percent just hours after Tuesday’s opening. According to Reuters, the drop was caused by Nike’s controversial new “Just Do It” ad campaign which centers around Colin Kaepernick, the former NFL player who sparked controversy two years ago by taking a knee during the national anthem to protest police brutality.

The new ad, which features a black and white close up of Kaepernick with the caption “Believe in something. Even if it means sacrificing everything,” caused protestors to take to social media and call for a boycott on the famous athletic brand.

Believe in something, even if it means sacrificing everything. #JustDoIt

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“Nike is not a stranger for backing sporting personalities who take views and act on them. Politicizing sport is likely to result in polarizing demographics,” said John Guy, an analyst at Mainfirst Bank in London during an interview with Reuters. “Freedom of speech is one of America’s core tenants, so placing this freedom within a sporting context for a brand as big as Nike will always make headlines,” he added.

Nike has waded into the discussions around social issues before. According to a report from Bloomberg, the company made headlines shortly after President Trump’s inauguration, launching a series of advertisements titled “Equality” which featured brand ambassadors such as fencer Ibtihaj Muhammad wearing a hijab and Chris Mosier, a transgender triathlete, among others.

While controversial, some experts believe Nike’s campaign to be more calculated than many might think at first glance. Love him or not, Kaepernick, who previously played for the 49ers, remains one of the country’s most popular athletes.