Tesla's plan to begin production of a lower-cost sedan — the Model 3 — will boost sales volume, Whiston said, but with an expected base price of $35,000, it's still pricier than the average new car. It'll also face competition from electric offerings from mainstream automotive manufacturers, such as General Motors' Chevrolet division's upcoming Bolt EV, which promises a range of more than 200 miles. That's been one of the big differentiators between Tesla and its EV competitors — it's the only one already featuring a battery that has the range of a gas-powered car, at 240 miles on a full charge.
"Tesla is aiming for about 50,000 sales this year and wants 500,000 in 2020, when the gigafactory is fully operational," Whiston said. "But growth is not free. The gigafactory alone will cost $5 billion."
Tesla reported on Tuesday that it had delivered a company record 11,603 vehicles in the third quarter and plans to build between 15,000 and 17,000 vehicles in fourth quarter, and to deliver between 17,000 and 19,000. That would mean 50,000 to 52,000 deliveries for the year.
In its post-earnings conference call on Tuesday, Tesla said it is on track to unveil the Model 3 in late March 2016, and that its gigafactory construction and production are ahead of schedule. The company said its current plans to begin cell production in 2016 for Tesla Energy products at the gigafactory are several quarters ahead of its initial plan.
"There's a lot of potential to change the world here," Whiston said. "But automaking is a cyclical business, and we haven't seen this company go through a recession yet. In a recession, the stock could drop."
Story updated to include Tesla third quarter results, released after the close on Tuesday.
— By Joe D'Allegro, special to CNBC.com