Donald Trump wipes off $1bn from Boeing's stock market value with single tweet

Minutes before he sent the tweet, the CEO of Boeing was reported to have expressed doubt about Mr Trump's plans on international trade

Donald Trump’s words do not only cause a storm on social media, they also affect capital markets.

The President-elect’s latest feud is with Boeing, the major US manufacturer of airplanes. In a tweet, he said that the costs for the company’s new Air Force One government plane were “out of control” at $4bn and the government contract should be cancelled.

The tweet was sent shortly after the Chicago Tribune posted a story that showed the company's CEO expressing doubt over Mr Trump's plans on international trade.

Before the president-elect's tweet, the company was trading at $152.16 per share. After the tweet, it fell close to 1 per cent during pre-market trading on Tuesday to $149.75 per share, according to FactSet.

The bump was temporary as the share price has since recovered and is still up about 5 per cent on the year to date, but the dip shows the knee-jerk reaction from investors when the President-elect expresses his views on a company.

Boeing’s market capitalisation at Monday’s stock market close (5 December) was $93.91bn, according to data from Reuters.

Today’s 0.84 per cent fall in the share price of the aerospace giant in early US trading therefore represents a decline in the value of the company of almost $1bn.

"We are currently under contract for $170 million to help determine the capabilities of these complex military aircraft that serve the unique requirements of the President of the United States," Boeing spokesman Todd Blecher said in a statement. "We look forward to working with the U.S. Air Force on subsequent phases of the program allowing us to deliver the best planes for the President at the best value for the American taxpayer."

Boeing won a contact in January to start working on a new fleet of government aircraft called Air Force One.

It won an initial contract worth almost $26m to reduce risk and lower costs.

The former CEO of Boeing, Jim McNerney, sits on Mr Trump’s transition team.

Asked by reporters at Trump Tower on Tuesday morning about his tweet, he said the costs were “ridiculous”.

Mr Trump did not say he had phoned the current CEO of the company, Dennis Muilenburg.

Mr Muilenburg has only made measured comments about Mr Trump’s plans on international trade. Speaking at a manufacturers’ association in Illinois last week, he said: “I'm not a political pundit or prognosticator – we have too many of those – but anyone who paid attention to the recent campaigns and the election results realises that one of the overarching themes was apprehension about free and fair trade.”

The Chicago Tribune posted the comments in an article the same morning of the tweet.

The President-elect has recently intervened with businesses, phoning up air conditioning plant Carrier in Indianapolis and persuading them to save almost half of its jobs from moving to Mexico.

He also claimed he had persuaded Ford to halt its plans of moving to Mexico, but Ford later clarified it had no intention of leaving and was only considering moving one production line.