Tesla (NASDAQ:TSLA) stock is up by about 5x year-to-date. While Tesla's fundamentals have improved in recent quarters- with margins and deliveries trending higher, much of the stock price gains have come from the expansion of Tesla's valuation multiple. Investors are betting that Tesla's lead in the EV and self-driving software space – two of the most powerful trends in the auto market – will help it shape the future of transportation. However, Tesla's stock has a considerable downside if this story doesn't play out. Below, we outline a scenario that could see Tesla stock decline by about 65% from current levels by the year 2023 – driven by stronger competition from mainstream automakers, the emergence of a strong challenger in the self-driving space, or weaker than expected sales of Tesla's new models.