Tesla shares tumbled in extended trading Wednesday after the EV maker's quarterly results fell short of Wall Street’s expectations and CEO Elon Musk warned of a "few rough quarters" ahead. Monitor these key chart levels.

The agreement could bolster the company's unprofitable contract manufacturing business, but Samsung faces challenges securing other large customers.

President Donald Trump took a break from his bitter public feud with Elon Musk by offering support to Tesla in an early morning post on Truth Social.

Tesla is scheduled to report its second-quarter results after the market closes on Wednesday, with investors expecting the electric vehicle maker's stock could make a sizable move.

Bloomberg journalists discuss today's biggest winners and losers in the stock market. Listen for analysis on the companies making news on Wall Street.

Tesla's stock was trading near $252 at Friday's close. Plus: The United States is now an emerging market. Invest accordingly.

Tesla has normally been a good investment. While it hasn't always outperformed the market, the automotive stock has generated returns of around 1,700% over the past decade, while the S&P is up around 200% over that time frame. Tesla's good years have more than outweighed the bad ones during that stretch.

Tesla shares rose early Tuesday after gaining on Monday, but gains didn’t last as the car maker tries to come out of its post-earnings dip. Shares of the electric-vehicle maker traded as high as $326.

For example, the stock currently trades at over 15 times sales. Toyota presently generates higher gross profit margins than Tesla, but trades at a price-to-sales multiple (P/S) of less than 1.

Shares of Tesla (NASDAQ: TSLA) climbed higher on Monday. The electric vehicle (EV) maker's stock gained 3% as of market close, but had jumped as much as 4.6% earlier in the day. The spike comes as the S&P 500 (SNPINDEX: ^GSPC) was flat and the Nasdaq Composite (NASDAQINDEX: ^IXIC) rose 0.3%.

Discover how Tesla, Inc.'s aluminum-ion batteries promise faster charging and sustainability but face competition. Click for my TSLA stock update.