Tesla stock soared in the months after the November presidential election because investors were convinced Donald Trump was about to do massive favors for his largest financial backer, Tesla CEO Elon Musk.

Shares of Tesla dropped by 14.2% as the market closed Thursday, the electric vehicle company’s 11th-worst day on the market ever. At one point in Thursday’s back-and-forth, Trump threatened the federal contracts that funnel billions toward Musk’s companies.

As Elon Musk and Donald Trump take jabs at each other online, their respective businesses are plummeting in value.