For 21-year-olds graduating from top universities, there’s a new reason to start out in investment banking — six-figure starting salaries.

Banking has always been among the top paying jobs for fresh graduates, but $15,000 salary hikes at JPMorgan, Citigroup and Barclays — to $100,000 — in the past month have set a new bar for an industry facing a retention crisis among young recruits.