Tesla's stock was down 7.4% to $178.89, but has since pared some of its losses and is now down 6.3%.
It's unclear what prompted the sell-off, but shares began to tumble in the last half hour.
Baird analyst Ben Kallo downgraded Tesla to neutral, from outperform, saying the stock's performance so far limits the upside in the near term, reports Forbes.
In other news, Jalopnik published a piece on a Tesla Model S car that caught fire on Washington State Route 167. Some are speculating that the sell-off is being driven by a video of the Tesla Model S on fire, arguing that it shows problems with the car's battery.
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