The world's largest investor is betting on traders in their twenties to help fix the market's biggest weakness

Mark Lennihan/AP What does a 25-year old know about trading bonds? Maybe enough to help one investing giant solve a problem that Wall Street can't seem to get its head around.  BlackRock, which manages $4.6 trillion in assets, has a team of young traders thinking of ways to apply electronic trading to markets where it's not yet prevalent. The program pairs young staff — the firm calls them "medium-experienced" — who are more adept at using technology with more experienced hands who know ...