What happened
Shares of JPMorgan Chase (JPM -1.05%) declined by 5% on Friday, after news broke that CEO Jamie Dimon required an emergency heart operation.
So what
Dimon needed the operation to repair an acute aortic dissection, or a tear in the aorta, the inner layer of the large blood vessel branching off the heart. The procedure was successful, and Dimon was reported to be recovering well.
Co-presidents and chief operating officers Gordon Smith and Daniel Pinto will lead the company in Dimon's stead.
"We have been working hand-in-hand with Jamie and the Board over the past two years to help lead our company," Pinto and Smith said in a statement to JPMorgan employees. "This is in addition to directly running the firm's Corporate & Investment Bank and Consumer & Community Banking businesses, which represent the majority of the firm's businesses."

Concerns regarding CEO Jamie Dimon's health led investors to sell shares of JPMorgan Chase on Friday. Image source: Getty Images.
Now what
Dimon is perhaps the most respected among the major bank executives. He led JPMorgan Chase through the financial crisis, and the company's more conservative use of leverage under his watch allowed it to avoid the worst of the Great Recession. In turn, JPMorgan Chase was able to scoop up failed competitors on the cheap and emerge stronger from the crisis.
If Dimon is unable to resume his duties as CEO, it would be a significant loss for the company. Still, JPMorgan Chase intends to press forward with Smith and Pinto at the helm.
"Just last week, the firm hosted our Investor Day, where we provided comprehensive updates on our strategy and priorities going forward," Pinto and Smith said. "We will continue to execute on all of these plans."