159,889 Wall Streeters are crowding auditoriums and classrooms around the world to take a grueling 6 hour test. If they pass it will change their lives. Half of them will fail.

Thousands of Wall Streeters will crowd gymnasiums and auditoriums around the world to write a grueling 6-hour exam on Saturday. Their odds of passing are less than 50%.

All three levels of the Chartered Financial Analyst exam are administered twice a year in 174 countries around the world, and this Saturday, 159,889 people are registered to take the test.

That's the highest number of registrants on record, according to the CFA Institute, which administers the exam.

Kurt Schacht, a managing director at the CFA Institute, said that interest in the exam has been growing pretty steadily throughout his ten years with the institute. Much of that is fueled by growth in Asia, which on Saturday will account for 43% of test takers.

He said that becoming a CFA charterholder will be a leg up for anyone hoping to build a career in investment management.

And as for other credentials, like MBA degrees, he said, "I honestly think there is no comparison in terms of the cost-benefit analysis." (The CFA costs $2,300 altogether, including registration fees and test fees.)

But the tests are tough. Last year, only 46% of people passed the tests - or 42% of Level I test takers, 46% of Level II test takers, and 54% of Level III test takers.

Level I tends to have the lowest pass rate, Schacht said, because that's the stage where the amateurs are weeded out from the serious players.

"There's a great demand on the employer side for people that make it through this course of study, and I think that's all reflected in how difficult it is," he said.

Only about one in five people who start the CFA program make it through all three levels and successfully complete the other requirements to become charterholders, he said.

Here are the historical pass rates, dating back to 1963, from the CFA Institute:

Good luck, everybody!