Walk into an airport bookstore and you might spot a 2,000-year-old war manual sitting next to books about getting rich. The Art of War, credited to a Chinese general called Sun Tzu, has somehow become a Wall Street favorite. Why would traders care about ancient battles?

Here’s the twist: for a war book, it doesn’t love war. It took shape during China’s Warring States period, when rival kingdoms fought to survive, and it treats fighting as expensive and risky. The best win? Skipping the fight entirely: “supreme excellence consists in breaking the enemy’s resistance without fighting.”

Its most famous line, “All warfare is based on deception,” sounds like a movie villain’s motto. In context, it’s really about planning: keep your opponent guessing and do your homework first. As the book puts it, “the victorious strategist only seeks battle after the victory has been won.”

That’s the part Wall Street loves. (This is my reading, not Sun Tzu’s; he never saw a stock chart.) Think of it like a test: your grade is mostly decided before you walk into the room. Investors do their studying with ideas like Benjamin Graham’s “margin of safety,” buying only when the price leaves room for being wrong.

But markets aren’t battlefields. One investor’s win doesn’t have to be another’s loss. And Sun Tzu’s love of tricks can get you in legal trouble: placing fake orders to fool other traders, called spoofing, is banned in U.S. futures markets. Borrow the prep. Skip the tricks.

So, before your next big decision, whether it’s an investment, a college application, or a job offer: have you already won it on paper, or are you just hoping to win once you’re in it?