Jefferies now prefers Antofagasta over copper peer Kazakhmys and has downgraded its rating for the latter from 'buy' to 'hold'."Our preference this year for shares of Kazakhmys over shares of Antofagasta has been based entirely on relative valuations (Kaz is much cheaper). However, after reviewing 1H12 operating results, we conclude that Anto's valuation premium relative to Kaz is fully justified, and we are downgrading shares of Kazakhmys," Jefferies said on Thursday.The broker has reduced its target price for Kazakhmys from 900p to 650p. As for Antofagasta, its target price has been hiked from 1,050p to 1,200p, though a 'hold' recommendation has been maintained. Nomura has reiterated its 'buy' rating and 1,300p target price for car insurance group Admiral highlighting the firm's strong first-half results and continued claims 'stability'."We are encouraged by the underlying results coming ahead of expectations, and although UK policy count is somewhat slower than our estimate, it is to be expected given more competitive market conditions in the UK," Nomura said. Investec has placed its 'buy' recommendation and target price for Sir Martin Sorrell's media giant WPP under review after the group scaled back its full-year guidance as second-quarter results came in below expectations.Investec said that WPP's shares have re-rated on the back of better macro sentiment recently and so they would need positive sentiment or a catalyst to run further. Charles Stanley reckons that troubled sports retailer JJB Sports will likely follow in the path of High Street shop Blacks Leisure which went into administration and was sold earlier this year."Having consistently urged investors for the past 2.5 years to avoid the stock, seeing little equity value left in the company, we now put our recommendation under review with a view to suspending or ceasing coverage," said analyst Peter Smedley.BC