Bloomberg reported JPMorgan Chase & Co. Chief Executive Officer Jamie Dimon told Congress the bank let traders take risks they didn’t understand, but did not answer questions about more than $2 billion in trading losses.

According to the report, Dimon expressed regret over losses in the bank’s chief investment office, saying that its trading strategy was “poorly conceived and vetted” by senior managers who were “in transition” and not paying adequate attention.
 
Dimon will make his first of two appearances on Capitol Hill to face lawmakers probing how the largest and most profitable U.S. bank could have taken such risks after coming through the 2008 financial crisis largely unscathed, according to the Bloomberg report.