Prosecutors had hoped that a string of e-mails exchanged in 2007 between Ralph Cioffi and Matthew Tannin, the former Bear Stearns hedge fund managers acquitted of fraud on Tuesday, would present a convincing case that the two men had lied to investors.

The e-mail traffic concerned the subprime mortgage market, which would help bring down the funds they worked for – as well as Bear Stearns itself.