Shares in Tesla tanked by as much as 7.6% in premarket trading Monday after its CEO Elon Musk said he is forming a new American political party, provoking an irate response from US President Donald Trump.

Tesla stock fell almost 7% in premarket trading on Monday after Musk announced a new political party.Tesla investors are frustrated with his political involvement, wrote analyst Dan Ives.Musk's feud with Trump makes investors worry about Tesla's future,

Mr. Musk’s involvement in politics and his financial support for the president’s campaign was once seen by investors as a benefit to Tesla, fueling a steep rise in company shares after the election last year. That association has now turned into a liability. Tesla shares are down 40 percent from their peak in December.