Check out which companies are making headlines after the bell Monday:
Tesla shares continued to slide after the bell, having ended the regular session about 5 percent lower after its Model D received negative investor-reception.
T-Mobile - Shares fell about 2 percent in extended trading after French telecom firm Iliad said it had dropped its bid to buy the U.S. mobile carrier. Industry rivals Sprint and Verizon rose after the bell, while AT&T lost nearly 1 percent.
Barracuda Networks gained about 1 percent after adding more than 9 percent during the regular session on news that it beat earnings and revenue estimates.
Semiconductor maker Microchip Technology gained nearly 2 percent, having ended the normal session about 3 percent lower after it cut its quarterly sales outlook. Fellow chipmaker Advanced Micro Devices plunged more than 9 percent in after-hours trading.
GoPro - The stock tumbled as much as 16 percent earlier after a French journalist suggested that Formula 1 legend Michael Schumacher's injuries in a ski accident last year might have been caused by a wearable camera made by the company, Reuters reported. The famed racecar driver denied the report in a tweet Monday afternoon.
The wearable camera maker was last down more than 2 percent in after-hours trading.
Gold mining shares, including Royal Gold, AngloGold Ashanti and Newmont Mining, rose after the bell, as gold futures gained more than 1 percent in electronic trading, boosted by Monday's steep stock market selloff.
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