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.

Tesla shares sank Monday after CEO Elon Musk announced he would form a new political party in an escalation of his feud with President Donald Trump.

President Donald Trump and Elon Musk are trading public insults after the Tesla billionaire suggested he'll create a new political party, "America Party."