Last week, legendary investor Warren Buffett disclosed that he upped his stake in Personal Finance Growth Portfolio holding Delta Airlines (NYSE: DAL). Buffett bought more than 5 million shares of DAL through his investment company, Berkshire Hathaway (NYSE: BRK.A). Berkshire now owns nearly 71 million shares of DAL worth $3.6 billion, about 10% of Delta’s stock market value.

That may seem like inopportune timing given the crash of a Boeing (NYSE: BA) jetliner over the weekend that killed all 157 passengers aboard. In addition to the immeasurable loss of life, shares of Boeing fell 10% in the two days following the crash, quickly erasing $20 billion in shareholder value.

Several nations have announced they will suspend use of the aircraft in question until the cause of the crash is known. Government leaders in the U.S., including presidential hopeful Senator Elizabeth Warren (D-MA), are calling for a similar ban here at home.

In response, Boeing stated that it has full confidence in the 737 Max jet despite this being the second fatal accident in five months involving that model. Regardless of how the inquiries turn out, this degree of attention will bring unwanted scrutiny to the entire airline industry.

That being the case, did Buffett make a mistake loading up on an airline stock just days before the entire sector got thrown into chaos?

Buffett’s 5 Rules for Success

Buffett is famous for the long-term nature of his thinking. Over the years, he has made clear his aversion to investment trends. Instead, he adheres a strict set of beliefs that have made him one of the richest men in the world.

Fortunately for investors, Buffett shares his secrets every year through his annual letter to Berkshire Hathaway shareholders.

Below are five stock-picking tips drawn from Buffett’s shareholder letters and his numerous interviews over the years that explain why the events of the past week probably would not change his approach to sinking another $265 million into shares of Delta:

1. Strong stocks are worth paying for: “It’s far better to buy a wonderful company at a fair price than a fair company at a wonderful price,” wrote Buffett in his 1989 shareholder letter. The idea is that the bargain price probably won’t turn out to be such a steal over time. “For example, if you buy a business for $8 million that can be sold or liquidated for $10 million and promptly take either course, you can realize a high return,” Buffett wrote. “But the investment will disappoint if the business is sold for $10 million in 10 years and in the interim has annually earned and distributed only a few percent on cost.”
   
   
2. Patience is crucial: “I call investing the greatest business in the world because you never have to swing,” said the Oracle of Omaha in 1974. “You stand at the plate, the pitcher throws you General Motors at 47! U.S. Steel at 39! And nobody calls a strike on you. There’s no penalty except opportunity lost. All day you wait for the pitch you like; then when the fielders are asleep, you step up and hit it.”
   
   
3. Don’t invest in something you don’t understand: “If we have a strength, it is in recognizing when we are operating well within our circle of competence and when we are approaching the perimeter,” Buffett wrote in Berkshire’s 1999 shareholder letter. “Predicting the long-term economics of companies that operate in fast-changing industries is simply far beyond our perimeter,” he added. “If others claim predictive skill in those industries—and have their claims validated by the behavior of the stock market—we neither envy nor emulate them; we just stick with what we understand.”
   
   
4. You don’t have to be a pro to make money in the market: This one goes hand-in-hand with point No. 3. “You don’t need to be an expert in order to achieve satisfactory investment returns,” wrote Buffett in his 2013 shareholder letter. “But if you aren’t, you must recognize your limitations and follow a course certain to work reasonably well.”
   
   
5. Don’t be afraid to bet against the herd: “Occasional outbreaks of those two super-contagious diseases, fear and greed, will forever occur in the investment community,” wrote Buffett in his 1986 shareholder letter. “The timing of these epidemics will be unpredictable,” he added. “And the market aberrations produced by them will be equally unpredictable, both as to duration and degree. Therefore, we never try to anticipate the arrival or departure of either disease. Our goal is more modest: we simply attempt to be fearful when others are greedy and to be greedy only when others are fearful.”

For all those reasons, I’m confident Buffett is losing no sleep over his increased exposure to the airline industry. He knows what works for him and isn’t about to change the way he manages his portfolio.

Keep in mind that Buffett has been at it for over 60 years, so your idea of long-term may not be the same as his. If you don’t have decades to earn the type of wealth that will get you to where you want to go, then you may need to consider an investment strategy that offers faster results.

Which brings me to my colleague Genia Turanova.

Genia is the chief investment strategist of the trading service Fast-Track Millionaire. Genia knows how to pinpoint fledgling growth companies that are flying under the radar. She steers her followers to these “rocket stocks” right before they blast off. Hence the term fast-track.

Genia has found a little-known biotech that Warren Buffett would love. This Swiss-based company is developing a gene-editing tool that’s on the verge of revolutionizing health care. As Buffett teaches us, timing is crucial. The time to invest in this biotech’s stock is now, before the Wall Street herd catches on and bids up the share price. Click here for details.