JPMorgan Chase just reshuffled the deck on its leadership succession. Doug Petno and Troy Rohrbaugh were named co-presidents on June 25, with each executive taking command of distinct halves of the largest US bank by assets.

Petno will oversee the commercial and investment banking divisions. Rohrbaugh gets consumer and community banking. And Jamie Dimon, the man who has run JPMorgan since January 2006, signaled he plans to stay in the CEO chair for at least another three years before possibly shifting to an executive chairman role.

Shares rose 1.7% on the news.

The exit that changed everything

The catalyst here is the departure of Marianne Lake, who retired after more than 25 years at the bank. Lake had long been considered one of the top internal candidates to eventually replace Dimon, and her exit effectively cleared the runway for Petno and Rohrbaugh to emerge as the two leading contenders.