Fresnillo's shares surged after UBS rated its stocks a 'buy', saying it was well placed to handle the volatility of gold and silver prices by keeping costs down and generating free cash flow. Wood Group rallied after Investec raised its target price to 900p from 800p, noting the company's strong performance in the first half on the back of demand for its services in engineering and operations and maintenance. G4S climbed following reports activist hedge fund Cevian Capital had become a major shareholder in the security firm.Old Mutual slumped after Nomura downgraded the stock to 'neutral' from 'buy' as it sees "better value elsewhere in the sector". Prudential retreated after rising to an all-time high on Monday when it reported a jump in first-half profits. Barclays declined following reports it was reviewing its United Arab Emirates retail arm for potentially selling the business. FTSE 100 - RisersFresnillo (FRES) 1,156.00p +4.81%Wood Group (John) (WG.) 923.00p +3.13%G4S (GFS) 251.40p +2.99%International Consolidated Airlines Group SA (CDI) (IAG) 321.00p +2.82%BAE Systems (BA.) 451.80p +2.59%Rio Tinto (RIO) 3,257.50p +2.05%Resolution Ltd. (RSL) 329.80p +1.88%Rexam (REX) 515.50p +1.78%Petrofac Ltd. (PFC) 1,295.00p +1.65%AstraZeneca (AZN) 3,320.50p +1.51%FTSE 100 - FallersOld Mutual (OML) 196.00p -2.63%ITV (ITV) 162.50p -1.81%Prudential (PRU) 1,218.00p -1.14%Aggreko (AGK) 1,700.00p -0.76%William Hill (WMH) 442.40p -0.74%Standard Life (SL.) 367.30p -0.73%Barclays (BARC) 283.05p -0.68%Standard Chartered (STAN) 1,602.00p -0.65%United Utilities Group (UU.) 703.50p -0.64%London Stock Exchange Group (LSE) 1,561.00p -0.64%RD