Execution Noble thinks it’s time for a breather on the technology company, and downgrades the stock to a “sell” with a fair value of 300p. The broker says that ARM remains well placed to outperform the semi-conductor industry, and will continue to expand into new end markets, but the current value of 29 times 2012 core earnings forecasts is hard to justify.

RBS has downgraded the supermarket to a “hold” from a “buy”, with a target price of £3.82, after shares reached its previous target of £3.70. The broker says it does not see any near-term triggers that could change its forecasts, and prefers peers Tesco and Morrisons. It predicts a 1.1 per cent rise in sales growth at the firm’s quarterly results in October.

Standard & Poor’s has initiated coverage on the temporary power supplier with a “hold” rating and a target price of £17.00. Analysts believe Aggreko’s exposure to developing markets means continued demand for its services, and thinks growth could accelerate in the next five years. However, S&P sees potential for earnings disappointment.