Musk said he wants to form the America Party. A third party has never won the presidency, but they have influenced elections, experts say — mostly as spoilers.

Elon Musk's net worth has taken a $15.3 billion hit after the Tesla CEO announced he was to form a new political party. The news sent ripples through financial markets and spooked investors concerned about Musk's political ambitions and possible implications for Tesla's brand and business operations.

Tesla stock lost nearly 7% Monday after Elon Musk announced plans of launching the “America Party.” William Blair downgraded TSLA shares.