4. Martin Blessing – Dashed Hopes

When former Commerzbank boss Martin Blessing (pictured above) joined UBS in 2016, he was quickly touted as a potential replacement for CEO Sergio Ermotti. His advancement from running the wealth manager's humming domestic arm to its $2.1 trillion private bank, together with Tom Naratil, only increased the odds. 

Instead, Blessing couldn't find his feet after the January 2018 promotion, as finews.com reported. Critics of the German banking veteran chalked this up to his lack of experience with wealthy clients (Blessing's background is largely corporate banking).

The 56-year-old's departure in October also has to do with the surprisingly quick availability of Credit Suisse star Iqbal Khan: just three months after inheriting Blessing's job, Khan had already begun making major organizational changes aimed at making UBS' flagship private bank more nimble and energetic.

Officially, Blessing is at UBS until year-end. The ex-McKinsey consultant and partner of German star banker Dorothee Blessing – she is responsible for J.P. Morgan's investment bank in Germany, Austria, and Switzerland – isn't likely to disappear entirely.