Money managers poured into the Gulf region till Saturday’s unprecedented attack on Saudi Arabia’s key oil facilities. That drove record gains for bonds in August as they sought refuge in securities boasting an average credit score of A+ amid global trade tensions. According to a Bloomberg Barclays index, Saudi Arabian bonds handed investors the biggest loss, about triple that of Qatari securities. The strikes in Saudi Arabia could escalate into a showdown, with the kingdom and U.S. on one side, and Iran and proxy groups from Yemen to Lebanon, on the other. Iranian-backed Houthi rebels in Yemen claimed responsibility for the assault and warned that oil installations in the Arab nation remain a target.