Musk has been able to play off Tesla's struggles for over a year now because the stock has been astonishingly resilient. Neither political gaffe nor falling deliveries has knocked Tesla off its upward trajectory, but Monday's selloff may be a sign of a changing sentiment.

Elon Musk said he’s carrying out his threat to form a new political party after his fissure with President Donald Trump, announcing on social media that he would form the America Party in response to the president’s sweeping tax cuts law.