Decades-long ties to Madoff cost JPMorgan $2.6 billionCredit: Reuters/Neil Hall 1 of 4. Workers are reflected in the windows of the Canary Wharf offices of JP Morgan in London September 19, 2013. Even as the bank cut its exposure to Madoff’s fund to minimize its losses it what ended up being a $17.3 billion Ponzi scheme, JPMorgan never shared its doubts with U.S.