A little-known Florida-based drones company said on Wednesday it had appointed Donald Trump Jr as an adviser – then saw its stock price surge.

“Don Jr joining our board of advisors provides us unique expertise we need as we bring drone component manufacturing back to America,” said Allan Evans, chief executive of Unusual Machines.

By mid-morning on the New York stock exchange, company shares had climbed as high as $11.67, more than double the day’s opening price.

Unusual Machines also said Trump Jr, the oldest son of the president-elect, was among its investors. A filing with the US Securities and Exchange Commission listed Trump Jr as the second-biggest shareholder.

In a press release that described Trump Jr as “a globally recognized business leader” and “best-selling author”, Evans said he would “bring a wealth of experience”.

Trump, typically referred to as Don Jr, has spent most of his adult life working for his father’s company, the Trump Organization, on real estate and branding. But he has risen to political prominence since his sister Ivanka Trump and her husband, Jared Kushner, distanced themselves from Donald Trump following his defeat by Joe Biden in the 2020 presidential election and incitement of the January 6 attack on Congress by Trump supporters who tried in vain to overturn his loss.

This year, Trump Jr was widely held to have helped steer the Ohio senator, JD Vance, onto the Republican ticket which defeated the Democratic ticket of the vice-president, Kamala Harris, and her running mate and Minnesota governor, Tim Walz.

On Wednesday, Trump Jr said: “The need for drones is obvious. It is also obvious that we must stop buying Chinese drones and Chinese drone parts. I love what Unusual Machines is doing to bring drone manufacturing jobs back to the USA.”

That was in line with statements from his father the president-elect, who has long said he will impose hefty tariffs on Chinese imports.

Unusual Machines, however, says in its SEC filing it “has been heavily dependent on Chinese imports for our products and operations”.

Referring to brands of drones and equipment, it said: “A substantial majority of Rotor Riot’s products are manufactured, directly and indirectly, using Chinese vendors. Fat Shark’s primary contract manufacturer is Shenzhen Fat Shark Technology Ltd … which is located in Shenzhen, China.”

Unusual Machines did not immediately comment further.