Tesla (TSLA 5.34%) is a company not easily ignored. Customers seem to love the company's well-designed electric vehicles (EVs) while the bulls seem quite pleased with the 33% stock price rise in the last 12 months. On the other end, the bears are very skeptical of the sustainability of its outsized stock price run. After all, Tesla stock delivered more than a 15-fold return in the last five years.

But for potential investors thinking about buying the stock now, it is crucial to consider whether it is safe to invest in Tesla today. While that is not going to be an easy exercise, investors should at least consider these two questions about the company and its stock.

Electric car charging.

Image source: Getty Images.

1. Is Tesla a durable business?

Tesla has reported some solid financials lately. After delivering its first profitable year in 2020, Tesla exceeded that performance in 2021. It delivered a record 936,222 EVs to customers, grew revenue and net profit by 73% and 665%, respectively, and expanded free cash flow by 80% to $5 billion. 

But note that the last paragraph started out by using the word "lately." It's useful to also be aware that Tesla had never delivered a profitable year until 2020. It has been on the brink of bankruptcy a few times, most recently from 2017 to 2019. But as the worldwide transition from combustion engines into electric engines gained steam, Tesla was favorably positioned to capture the pent-up demand. And it did, as is evident by its solid numbers.

While the 2021 result was remarkable, it is still an outlier more than a norm. The biggest issue is that two profitable years provide little assurance that Tesla can sustain that in the coming years. As the car industry is highly cyclical, an economic downturn (such as a recession) will cause consumers to tighten their belts. When that happens, average folks tend to delay their purchase of high-value items like a car, which could reduce industry volume. We still do not know how Tesla will perform in such an environment.

On top of that, the EV race has intensified in recent years. While Tesla is still the dominant player -- with a 21% global market share in 2021, according to Autocar -- incumbents like General Motors and Ford Motor Company have big plans to ramp up their production. Tesla also faces competition from Chinese car companies like BYD and Nio. The former, backed by Warren Buffett, sold 593,745 EVs in 2021. BYD also announced that it would stop producing combustion engine vehicles to focus on EVs and plug-in hybrids.

In short, Tesla must execute flawlessly in the coming years to maintain its market share and stay profitable. While we do not know whether the company can sustain its strong execution, there is one thing we do know for sure: Gone are the days when Tesla had the whole EV market to itself.

2. Does Tesla stock offer a margin of safety?

Ask any investor how to make money in the stock market, and the usual reply will be to buy a stock when the price is low and sell when the price is high. However, this argument is incomplete since an investor should also consider the intrinsic value of the stock. The key is to buy when the stock price is lower than the intrinsic value (and sell when it is above).

But estimating intrinsic value is not a simple task. Not only are there many methods to calculate the intrinsic value of a company, but every investor will use different variables to compute. It is fair to say that every investor will arrive at a different intrinsic value for the same company.

Enter: margin of safety. The idea is that when investors buy a stock at a price materially lower than its intrinsic value, they have room for errors in their estimation of its value. Even if they make mistakes, they generally lose little money since they buy the stock cheaply.

So is Tesla's stock cheap enough today to offer a margin of safety to investors? Let us consider a few simple metrics. As of writing, Tesla has a price-to-sales (P/S), price-to-book (P/B), and price-to-earnings (P/E) ratio of 21, 35, and 209. Comparatively, General Motors' P/S, P/B, and P/E ratios are 0.5, 1, and 5.9, respectively.

Tesla bulls will immediately cry foul, claiming that Tesla is fundamentally a different company from GM. While I agree with them that Tesla is not an average company, my argument is this: Is it worth 30 to 40 times more than GM? Or put it differently, is one Tesla equivalent to 30 to 40 GMs? To me, the answer is probably not.

Back to the original question: Is Tesla stock safe to buy?

There is no doubt that Tesla is a company with promising prospects. It is a leader in the EV industry and has significant investments in potentially major industries like autonomous vehicles, renewable energy, and others.

Still, I don't think it's safe to buy Tesla stock now with your hard-earned money. One reason is the company just turned profitable in 2020. It would need a few more profitable years before investors can safely assume the turnaround is permanent. Besides, its valuation is not cheap, which offers a very little margin of safety for investors.

So unless investors are looking for some adrenaline rush, they will be better off staying from the stock. And even if they are looking for such excitement, they can consider buying a Tesla car instead.