Tesla has been an exciting growth stock to own for years, and it has generated fantastic returns for investors. Although it hasn't been doing great recently, the stock is still up over 200% in five years. If Musk's vision for his company comes true, investing in Tesla stock could end up being really smart.

Tesla Inc.’s rough stretch in Europe continued as data from Germany and the U.K. showed the U.S.-based electric-vehicle maker’s sales were cut in half last month.