'Many challenges' await Ross McEwan, the new Chief Executive Officer at Royal Bank of Scotland (RBS), according to analysts at Exane BNP Paribas who kept their 'neutral' rating for the stock following Friday's results.Exane said that the internal appointment of McEwan is "unlikely to raise confidence that RBS is being managed to maximise returns for all shareholders". A downgrade by Societe Generale to 'sell' was also weighing on the share price on Monday.Panmure Gordon has hiked its target price for tour operator Thomas Cook following the firm's strong set of third-quarter results last week."We retain our 'buy' recommendation, highlighting improving underlying trading following the addition of new product, in addition to potential upside to cost saving targets. Thomas Cook was also given a lift by analysts at Citigroup who upgraded their rating for the stock from 'neutral' to 'buy'. Shares in Polymetal were under selling pressure on Monday morning after the stock's rating was lowered by UBS from 'buy' to 'neutral' after a strong run."Based on our calculations, Polymetal's market cap already prices in stability in the gold and silver markets and we downgrade the stock rating to 'neutral'," the broker said.BC