Jane Street’s Secrets Spill Into Open and Face Rivals’ Scrutiny

A poster with the WWII slogan “Loose Lips Sink Ships” long adorned the interior of Jane Street Group’s offices — an unsubtle reminder to staff of the secrecy prized by one of Wall Street’s most profitable firms.

Now the 25-year-old trading powerhouse is in the glare of a global spotlight.

It’s a privately controlled company so clandestine that it doesn’t publicly identify a leader at the top. A staffer who once tried to track down an email list of governing partners recalled giving up, learning that Jane Street doesn’t want something like that circulating, not even to people working there. ...