After a young woman politely rejected John Fitzgerald Page, an Atlanta-based financial consultant and a former analyst, on Match.com, he let her know in an email what she would be missing. “I think you forgot how this works. You hit on me, and therefore have to impress ME and pass MY criteria and standards—not vice versa.”

Page, who’s also a part-time actor and personal trainer, continued: “I will even give you one free training session, so you don’t blow it with the next 8.9 on Hot or Not, Ivy League grad, Mensa member, can bench/squat/leg press over 1200 pounds, has had lunch with the secretary of defense, has an MBA from the top school in the country, lives in a Buckhead high rise, drives a Beemer convertible, has been in 14 major motion pictures, was in Jezebel’s Best dressed, etc. Oh, that is right, there aren’t any more of those!”

Page’s correspondent forwarded his email, and it eventually made its way to the news and gossip blog Gawker, where it generated nearly a quarter of a million page views and thousands of comments.

Page isn’t the only finance guy whose over-the-top ego has produced some rich internet fodder. Last year, a video résumé made by Yale junior Aleksey Vayner for UBS was widely circulated. It shows him bench-pressing 500 pounds, ballroom dancing with a sexy partner, and hitting a tennis ball 140 miles per hour, all with the overlaid mantra of “impossible is nothing.”

Though it takes a strong ego to succeed in the competitive worlds of business and finance (see the related slideshow, Ego Readings, to find out how Donald Trump, Warren Buffett, Martha Stewart, and others rank), having a supersize ego can obviously backfire, alienating colleagues and potential partners (needless to say, UBS did not extend an offer of employment to Vayner).

David Marcum and Steven Smith, co-authors of Egonomics: What Makes Ego Our Greatest Asset (Or Most Expensive Liability), say ego obviously helps motivate us, but when taken to an extreme, it can turn passion into overzealousness and stubborn, aggressive behavior. And such behavior can derail professional lives: According to the Center for Creative Leadership, a third of senior executives hit a wall in their careers due to problems of not being able to work effectively with others and “team build.”

Marcum and Smith cite several early warning signs that your ego might need some restraining: You’re too competitive; you’re unable to take criticism and get offended easily; and you’re constantly showcasing your brilliance.

“When our egos are out of control is when we are susceptible to poor judgment,” says Mathew Hayward, author of Ego Check: Why Executive Hubris Is Wrecking Companies and Careers and How to Avoid the Trap. As an investment banker for Australia’s premier investment bank, S.G. Warburg, in 1983, Hayward took a high-paying job out of college, bought a BMW, and dated a lingerie model.

“I basically thought that I was the best,” Hayward says. He was so high on himself that he began to think he was invincible at work and became sloppy, not doing thorough analyses of premiums for share prices for his customers. As a result, he was fired, and the experience inspired him to eventually leave finance, pursue a Ph.D. in organizational studies, and write Ego Check.

“I think people misunderstand humility, especially on Wall Street,” says Marcum. “They take humility for weakness. Genuine humility is a competitive advantage.”