Investec has upgraded its rating for RBS from 'sell' to 'hold', playing down concerns about the upcoming Scottish referendum which has led to the stock's recent underperformance against the wider banking sector."We believe any such event-specific weakness will unwind after 18 September as we anticipate a pro-Unionist vote," said analyst Ian Gordon.Numis Securities has cut its rating for pub group and brewer Greene King from 'buy' to 'add' after the company's first-quarter trading update on Wednesday.The broker has cut its profit forecasts by around 3% to reflect the later timing of new openings and lower margin assumptions.Investec is keeping faith with Thorntons despite a warning from the chocolate retailer about a potential slowdown in first-half sales.The broker reiterated its 'buy' recommendation and its 175p target price, saying the pre-tax profit was slightly better than it had expected.The recent rally in the housebuilding sector has further to go, according to The Share Centre, though growth could start to ease in the near term."The future looks broadly positive for the sector, and earnings are likely to continue to increase, but maybe not giving the same returns as we have seen in the last 18 months as a result of less artificial stimulus. Share prices however don’t fully reflect this, despite a strong run earlier in the year.”