Tesla's shares price declined 1.74% for the week on Friday, two days after posting declining profits for a third straight quarter amid increased competition and a pending loss of federal tax credits.

Tesla shares sank Thursday after CEO Elon Musk said the company could face a “few rough quarters” as it transitions to a future focused less on selling cars and more on offering people rides in self-driving cars.

Investors knew electric vehicle (EV) sales have been slumping for Tesla ( TSLA -8.44%). The EV leader announced a 13.5% year-over-year drop in second-quarter deliveries on July 2. Yet the stock is tanking today after Tesla reported its full second-quarter financial update today.

Tesla shares are down in premarket trading Thursday as more disappointing sales data is dragging on the stock along with the lackluster second-quarter earnings report Tesla released after the closing bell on Wednesday.

Tesla shares plunged as much as 10% in early trading Thursday as investors digested another dismal quarter of car sales – and CEO Elon Musk’s admission that slump may not end anytime soon.