Ten years ago, it was 2015 -- an eventful year. Nearly 200 countries agreed to reduce emissions and focus on renewable energy, Tom Brady and the New England Patriots were accused of underinflating footballs, and the Supreme Court affirmed same-sex marriage nationwide.

The world's top electric vehicle (EV) stock has still worked out incredibly well for shareholders; it soared 1,170% during the past five years (as of Jan. 8). But with its current market cap exceeding $1.2 trillion, is Tesla a company you should be buying right now?