Junior talent's new edge on Wall Street

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You've cracked the code, beating out scores of applicants for a coveted entry-level position on Wall Street.

Fast-forward 24 months, and you may have a lot more leverage than you think.

The reason: More and more junior-level employees are jumping ship to create start-ups, or join the ranks of private equity firms and hedge funds. In response, top investment banks are offering more attractive incentives to stay.

"They will give you a third-year analyst position. After that, they dangle the carrot and say, 'If you do a good job we can potentially promote you to direct associate without an MBA,'" said Wall Street Oasis founder Patrick Curtis, a former investment banker who runs an online community for students who are trying to break into a career in finance and industry professionals.

The big institutions are now scrambling to hold on to the best because they didn't anticipate so many workers would leave, Curtis said. The relatively handsome salary of "$120,000 a year is cheap labor for them," he added.

Wall Street Oasis recently ranked the best investment banks for careers based on thousands of its members' rankings.

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Evercore, Moelis & Company, Blackstone Group, BMO Capital Markets and Piper Jaffray comprised the top five in terms of career advancement. Wall Street heavyweights such as Goldman Sachs, Deutsche Bank and Credit Suisse made the top 10.

"I was a bit surprised at the order of the rankings but not at the banks that made the top list. It may be harder at the larger banks to get a sense of camaraderie and teamwork that some of the elite boutiques seem to have mastered," Curtis said.

"Given that many of those boutiques set you up for great exit opportunities into private equity or hedge funds, it wasn't that surprising that they were ranked in line or slightly above some of the bulge bracket banks by their employees," he added.

MBA degree losing influence?

Traditionally, an entry-level employee would work on Wall Street for two years and leave for business school. But with more firms overall looking to retain their brightest workers by grooming them from the ground up, there's less emphasis on the need for an MBA.

"In the past, people would actually help them in terms of the application process to guide them into an MBA program," said veteran Wall Street recruiter Andrea Baker, who has worked for major banking institutions since the mid-1990s

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"But they realized, why not keep them and promote them? Keep the organic talent," she added.

The Association to Advance Collegiate Schools of Business, a global nonprofit organization whose members include U.S. business schools, asks about MBA enrollment in its yearly questionnaire.

Of 233 U.S. business school respondents, the organization recently found fewer students are enrolling in full-time programs compared to five years ago. There was a higher rate of students registering in the 2011-2012 school year—when the figure reached nearly 31 percent.

"Overall there has been a shift in enrollment at U.S.-based AACSB schools at the MBA and specialized masters levels," said John Fernandes, president and CEO of AACSB International, in a statement. "Many are transitioning to part-time programs or specialized masters degrees."

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While the numbers suggest a modest decline in full-time MBA enrollment, there's still a significant portion of undergraduates trying to break into financial services. And there may be no better time to do so.

Preliminary data obtained by CNBC.com from Fordham University shows more than one in 10 from its spring 2014 class employed in the field. But, how long they'll stay in those first positions is anyone's guess.

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"Across the entire economy we have seen the time employees spend with an organization shrink over the past decades. People entering the workforce today have more flexibility to move jobs and industries," said Stefany Fattor, Fordham's director of experiential education.

"Students graduating now will likely have even more careers," she said. "I believe this is a result of many factors, including technology and the financial crisis."