Credit Suisse Collapse Burns Saudi Investors

DUBAI—Riding an oil-price boom last year, Saudi Crown Prince Mohammed bin Salman directed government-backed Saudi National Bank to make a $1.5 billion investment in Credit Suisse Group AG that his financial advisers harbored doubts about, according to people familiar with the matter.

Now, the Saudi investment is almost wiped out after Credit Suisse’s emergency merger with UBS Group AG. Credit Suisse’s meltdown also erased billions of dollars in investments made by Qatar’s sovereign fund and the Saudi-based Olayan family, making the Persian Gulf one of the biggest losers from a slide in financial stocks since the collapse of two U.S. banks last week.