Being Right Isn’t Enough: The Critical Role of Position Sizing in Investing

Imagine having access to tomorrow’s news today. Wouldn’t that be the ultimate investing edge?

That’s exactly what an experiment by Elm Wealth tried to test. They gave 118 finance students access to the next day’s Wall Street Journal front page—a full 24 hours before it went public. You’d expect instant profits, right?

Surprisingly, more than half of them lost money, and 16% went completely bust.

But here’s the twist: the problem wasn’t their market prediction skills. In fact, they got the market direction right 51.5% of the time—better than random chance. The real issue? Poor position sizing.

Leverage Without Discipline = Disaster
Most students bet aggressively—some used 20x, even 60x leverage—putting large portions of their portfolios on single trades. While the upside was tempting, just one bad call wiped them out. As Nithin Kamath aptly noted (in his recent linkedin post), “All it took was a single misstep.”

On the other hand, five seasoned traders ran the same simulation and walked away with +130% average returns. Why? They understood the art of survival. They bet small when uncertain, and big only when odds were clearly in their favor. That’s the real edge in trading—not news, not tips, not predictions.

The Ray Dalio Rule: “He who lives by the crystal ball…”

As Ray Dalio once said, “He who lives by the crystal ball will eat shattered glass.” The second part of the experiment’s write-up goes even deeper, referencing Nassim Nicholas Taleb’s thought-provoking idea:

Even if an investor had the next day’s news, they’d likely go bust in under a year.

Why? Because markets aren’t just about being right—they’re about being able to stay in the game. That means controlling downside, managing exposure, and never overestimating your certainty.

The Real Lesson: Betting Right vs. Betting Smart
Most retail traders obsess over predictions—trying to guess the next market move. But as this experiment shows, how much you bet matters more than what you bet on.

Professional money doesn’t just ask, “Am I right?” It asks, “What’s my downside if I’m wrong?”

Whether you’re managing personal wealth or running a fund, position sizing is the cornerstone of risk management. It’s not just a technical metric—it’s a survival tool. Without it, even the best insights will fail to translate into lasting wealth.

Because in investing, being right means nothing if you go broke before you’re proven right.