If you ever find yourself at a fan convention for the popular HBO series "Game of Thrones," look at the person next to you.

He or she just might control billions.

With nearly 20 million total viewers for the series, whose fifth season debuts on April 12, and 25 million copies in print of the George R.R. Martin books, the "Game of Thrones" franchise does not just appeal to comic-book geeks.

Powerful money managers get drawn in too, like Gavin Baker, head of Fidelity's $13 billion OTC Portfolio fund. Since Baker is conquering 98 percent of his peers over the last five years, investors should be curious about the financial lessons he and others are drawing from "Game of Thrones."

Here are a few of the key takeaways, other than the ultimate lesson of the bloody series: valar morghulis ("All men must die").

Lesson One: Listen for weak signals

"Be open to evidence that suggests that your view of the world is wrong," advises Baker. In the seven kingdoms of Westeros, the powers-that-be tend to dismiss the dangers gathering around them, such as the mysterious and vicious White Walkers to the north, and the fire-breathing dragons that are growing across the seas.

In the next book -- which Martin is toiling on right now -- one can only assume that these adversaries will come back to haunt those in power.

Lesson Two: Make dispassionate decisions

As behavioral economists always tell us, mixing emotion and investing is a bad idea.

So it is in Westeros. When the Stark family goes to war with the Lannisters, Robb Stark falls in love and breaks his previous engagement to the daughter of a powerful ally. "Meanwhile, his rival, Tywin Lannister, makes very few emotional decisions," says Baker.

Guess who comes out ahead?

Stark falls after being stabbed in the heart.

"He makes an emotional decision; that is the reason he dies," Baker says.