Shares of several big brokerages were slipping after analyst Richard Bove reissued sell ratings on three Wall Street firms. Bove, an analyst at Ladenburg Thalmann, cut his ratings to sell from neutral on Goldman Sachs ( GS ), Lehman Brothers undefined and Merrill Lynch ( MER ) on the belief that the firms will have disappointing earnings throughout the rest of the year, mainly from lost money on hedging strategies. The outspoken analyst -- normally a skeptic of the brokerages' business models, particularly as the credit and liquidity crisis intensified last year -- was more optimistic on the sector earlier this year. Bove has since retrenched on that optimism. "At the moment it appears that the pressures on the brokerage industry have increased for multiple reasons," he writes in an industry note on Thursday. Most notable, " while I remain convinced that the stress on the financial sector has been alleviated, I am just as convinced that the pressure on the economy has not eased."