Shares dipped nearly 5 percent Wednesday to $121.11, after rising Tuesday more than 3 percent.
The National Highway Traffic Safety Administration (NHTSA) is looking into two of the incidents to ensure Tesla batteries are not more prone to fires. The accidents were said to be sparked by "undercarriage strikes" from roadway debris.
Tesla CEO Elon Musk has previously announced that the cars will not be recalled. But the company has announced a readjustment of the motors to rise battery packs away from the road at high speeds, reducing friction and likeliness of fire.
Nissan has sold almost 90,000 electric cars and General Motors has sold almost 50,000 with no reported incidents. However, after the Tesla incidents, investors, media and consumers are growing wary of the safety of electric cars.
But Musk says the attention to Tesla is inflated, and maintains that Tesla has the "best safety record of any car on the road."