Self-described “long-term optimist” Elon Musk made another bold prediction about his car company. That isn’t necessarily good news for Tesla’s stock price. On Saturday, Musk tweeted that Tesla’s earnings could grow tenfold over the coming five years if its business execution is “outstanding.

Tesla stock has plummeted by more than 15%, meaning the company has suffered its worst day of trading in more than four years.

The EV maker has shed nearly half its value but still looks expensive compared with tech and auto peers.

After a slight rebound earlier this week, Tesla's TSLA stock is back to falling, keeping with its recent performance. Even U.S. President Donald Trump's purchase of one hasn’t done much to spark real momentum for the electric vehicle (EV) leader.

Tesla stock has fallen 51% from its high, but hedge fund billionaire Ron Baron still thinks the company will be worth $5 trillion within a decade. Tesla plans to introduce autonomous ride-sharing (robotaxi) services in several U.

Tesla stock closed down 3% at $240.68, while the S&P 500 and Dow Jones Industrial Average lost 1.4% and 1.3%, respectively. Tesla stock rose 7.6% on Wednesday after gaining 3.8% o

Trump told reporters he would write a check for the car, which retails for roughly $80,000, and leave it at the White House so his staff can drive it. The president also said he hopes his purchase will boost Tesla,

Tesla (TSLA) has lost about half of its market value, or $800 billion, due to the recently market selloff and its own struggling business. But its CEO Elon Musk remains the world’s wealthiest person,