As European stock markets rocket upward, private bankers from Zurich to London say they face a growing challenge to keep clients' feet on the ground. U.S. clients learn very early about the markets when they go to school. When Mr. Bischofsberger left for assignment in the United States several years ago, he said, Europe had few television programs that dealt with markets.
Temptation is everywhere.
Mr. Bischofsberger said, ''Clients see how stock markets have performed in the last two years and guess it will go on this way, and even if they are only rising at half this rate they will make money.'' Since autumn, the European markets' gains have been ''almost uninterruptible,'' said Bruce Russell, head of global research and investments at Barclays Private Banking in London. Germany's DAX index has moved from 3,800 to more than 5,000 since November. And in fringe markets like Finland, Portugal and Ireland, markets have risen more than 50 percent in the first quarter of l998. Meanwhile, Italian, Spanish and Portuguese investors who have been accustomed to double-digit returns from bonds, are now seeing yields shrink to 6 percent. Of course, European stocks have had their heady moments before.