Investec has cut its rating for Royal Bank of Scotland (RBS) from 'hold' to 'sell', saying it sees downside after a recent run in the share price."Following RBS' latest +16% six-week 'spike' we believe that the share price (once again) reflects a triumph of hope over reality and should duly correct," said Analyst Ian Gordon.Despite a number of headwinds, Johnson Matthey should be able to deliver double-digit underlying growth this year, according to Numis Securities which upgraded its rating on the stock on Thursday from 'hold' to 'add'.The broker said that Johnson Matthey enjoys a number of "favourable medium-term business drivers" and growth prospects look "more assured" than chemicals peer Croda.Online grocery group Ocado has a "unique and disruptive business model" in the UK food retail industry, according to JPMorgan Cazenove which initiated coverage of the stock with an 'overweight' rating and 500p.The US bank said that Ocado is the "best way to play the shift from property to IT as the key differentiating investment in food retailing".BC