Security solutions group G4S was performing well as it attempts to claw back some of the losses it has incurred over the last week - including today's gain, the stock is still down nearly 15% on last Wednesday. The group said on Monday that it will take a 35-50m pound loss on its Olympics contract. Fund manager Ashmore was a high riser after Goldman Sachs upgraded its rating on the stock to 'buy'. Silver and gold miner Fresnillo surged after notching up record levels of gold production in the second quarter, while silver output was up quarter-on-quarter. Meanwhile, RSA Insurance became a heavy faller after the miserable weather over the past few months put a dampener on its full-year underwriting performance. FTSE 100 - RisersAshmore Group (ASHM) 331.60p +2.98%G4S (GFS) 245.70p +2.38%Burberry Group (BRBY) 1,223.00p +2.26%Antofagasta (ANTO) 1,064.00p +1.92%Capital Shopping Centres Group (CSCG) 333.10p +1.74%Johnson Matthey (JMAT) 2,137.00p +1.62%Marks & Spencer Group (MKS) 323.30p +1.57%Fresnillo (FRES) 1,429.00p +1.49%Aggreko (AGK) 1,956.00p +1.45%Tullow Oil (TLW) 1,401.00p +1.37%FTSE 100 - FallersReed Elsevier (REL) 518.50p -2.72%Weir Group (WEIR) 1,471.00p -2.06%Rio Tinto (RIO) 2,870.00p -1.59%Evraz (EVR) 247.60p -1.20%HSBC Holdings (HSBA) 541.00p -1.17%United Utilities Group (UU.) 690.00p -1.15%IMI (IMI) 778.50p -1.14%Imperial Tobacco Group (IMT) 2,518.00p -1.06%Polymetal International (POLY) 840.00p -0.83%Hammerson (HMSO) 463.30p -0.79%NR