When Jean-Claude Erne talks about his career at Pictet Group, a private Swiss bank with 19 offices world-wide that manages assets for institutions and wealthy individuals, he emphasizes "the Pictet spirit," which he says helps explain the bank's success since its founding in 1805.

Mr. Erne says the bank has done well recently precisely because of its focus on asset and wealth management, and because it hasn't ventured into investment banking or commercial activities.