JPMorgan and the London Whale

In the spring of 2011, JPMorgan Chase realised that their synthetic credit portfolio (SCP), which represented less than 1% of the bank's total assets, had grown to become more than half of the bank's total risk. An article in the WSJ would soon make it public knowledge that the bank was in a difficult situation. How could an institution known for its diligence, which had survived the global financial crisis, and was led by a highly respected CEO (Jamie Dimon), end up in such dire straits?