Jack Latimer is a professional investor who used the outcomes of the the Leverage team's activities to make a series of lucrative investments. He first makes his presence felt by bugging Nate's condo. Soon after, he calls Nate, requesting the team take over contracts he had with the recently disgraced Reed Rockwell (The 15 Minutes Job) with a generous commission. Nate refuses, but suggests a face-to-face meeting. Latimer declines, and after making a few cryptic comments about Nate thinking he's a good guy, concludes the call without introducing himself.
Using his investment in VerdAgra (The Hot Potato Job) as a starting point, Hardison learning Latimer's name and compiles a dossier, which he gives to Nate at the end of The Boiler Room Job. It shows that Latimer is a farm boy who attended the University of Chicago on a scholarship, then started his own business in 1985 by mortgaging his house. Latimer runs an investment firm with assets worth millions of dollars. Other investments include Merced Financial (The Long Way Down Job), DuberTech (The Reunion Job), Wakefield Agricultural (The Inside Job), and Ernshaw Pharmaceuticals (The Juror #6 Job), all companies with personnel and/or practices exposed by the Leverage team. Nate is surprised to learn that rather than losing money on these investments, Latimer has made money.
Nate visits Latimer's home to confront him. Latimer tells him that three years earlier, his fund had money in Pierson Aviation. While keeping C.E.O. Steve Pierson under routine surveillance, he obtained video of a man handing Pierson a bag full of hard drives, and realized Victor Dubenich's insistence he'd been conned was true. Viewing Nate as what he terms a "market correction", Latimer invests considerable money in tracking the team and its activities, allowing him to anticipate their next move. Latimer makes an angry Nate an offer: he'll supply the names of companies who are covering up illicit activities if Nate gives him 24 hours notice before the team acts. Nate leaves, issuing a warning that Latimer should stay out of Nate's business.
For a time, Latimer goes quiet. He reappears following The Lonely Hearts Job, calling Nate with a potential new client: an engineer whose invention was stolen by a corporation. He proposes the team acquire the patent, but not before Latimer makes a few investments. Nate refuses, calling Latimer's offer a con. Latimer sighs, then makes a second call to an unknown person, informing him Nate has refused the offer. Latimer appears to receive orders, which he describes as "war".
- The 15 Minutes Job: Latimer calls Nate, offers him the opportunity to take over Reed Rockwell's contracts.
- The Boiler Room Job: Hardison shows Nate his dossier on Latimer, Nate visits Latimer's home to confront him.
- The Lonely Hearts Job: Latimer resurfaces, offers Nate a job helping an unnamed engineer. Nate refuses, leading Latimer to contact an unnamed collaborator.
- His last appearance is in the season four finale.