In the 100 days since Gerald Hassell was named chief executive and chairman of the world’s largest custodian, BNY Mellon has vigorously defended itself against accusations of wrongdoing in foreign exchange activities, ridden out a difficult third quarter in the markets, and is now facing a potential downgrade by credit ratings agency Moody’s.

The custodian, which has $25.9 trillion in assets under custody, welcomed Hassell to the position on August 31. The firm veteran, who has over 35 years' experience at the bank, replaced Robert Kelly, who had reached a mutual agreement with the board of directors to step down as chief executive. In a statement BNY Mellon cited the move as "due to differences in approach to managing the company".