Citigroup Inc., Bank of America Corp. and more than a dozen other firms told clients to purchase European energy producers and U.S drugmakers while selling banks and retailers, according to combined rankings compiled by Bloomberg. An investor who used $10,000 to buy companies in the highest-rated industries and bet on declines in the lowest since the advance began on March 9 lost everything and would owe as much as $6,000 to cover bearish trades, the data show.